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CVE-2026-80225

MEDIUM 5.3

Published 2026-09-16 · Last modified 2026-09-16

In NLnetLabs Unbound up to and including 1.26.0, a degradation of service vulnerability is present in the TCP/DoT reading procedure where there is no limit on consecutive reads. A malicious actor that can stream and sustain a rate of distinct uncached names over the TCP/DoT connection, monopolizes a single worker's entire event loop for as long as its writes stay ahead of the drain.

NO EXPLOITATION SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.5%chance of exploitation in 30 days · 41st percentile

○ In CISA KEV ○ Catalogued PoC

Impact if exploited

5.3CVSS 3.1 · MEDIUM

  • ConfidentialityNone
  • IntegrityNone
  • AvailabilityLow

What an attacker needs

  • ✓Access: Reachable over the network — no local access needed
  • ✓Privileges: No account or privileges required
  • ✓User interaction: No user interaction needed
  • ✓Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept

No public PoC is currently catalogued.

Search for new PoCs

Search GitHub now — results may be empty or unverified.

Tracked sources are checked daily for recent CVEs, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.

Data snapshot:

Affected

Vendors Nlnet Labs Nlnetlabs

Products Unbound

Weakness (CWE)

  • CWE-770: : Allocation of Resources Without Limits or Throttling

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References and research data (JSON)

Vendor product assessments

Showing 32 of 48 vendor product statements; 16 omitted. Read the full vendor advisory.

  • python3-unbound-0:1.26.1-1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • python3-unbound-0:1.26.1-1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-0:1.26.1-1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-0:1.26.1-1.hum1@src as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=src&distro=hummingbird-20251124&repository_id=public-hummingbird-source-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-0:1.26.1-1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-anchor-0:1.26.1-1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-anchor-0:1.26.1-1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-devel-0:1.26.1-1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-dracut-0:1.26.1-1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-dracut-0:1.26.1-1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-libs-0:1.26.1-1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-libs-0:1.26.1-1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-munin-0:1.26.1-1.hum1@noarch@public-hummingbird-aarch64-rpms as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=noarch&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-munin-0:1.26.1-1.hum1@noarch@public-hummingbird-x86_64-rpms as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=noarch&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-utils-0:1.26.1-1.hum1@aarch64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=aarch64&distro=hummingbird-20251124&repository_id=public-hummingbird-aarch64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-utils-0:1.26.1-1.hum1@x86_64 as a component of Red Hat Hardened Images · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]?arch=x86_64&distro=hummingbird-20251124&repository_id=public-hummingbird-x86_64-rpms

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://images.redhat.com/ Vendor guidance
    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • python3-unbound as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/python3-unbound

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-anchor as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound-anchor

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-dracut as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound-dracut

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-utils as a component of Red Hat Enterprise Linux 10 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound-utils

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound as a component of Red Hat Enterprise Linux 6 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • no fix planned: Out of support scope
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-libs as a component of Red Hat Enterprise Linux 6 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound-libs

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • no fix planned: Out of support scope
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound.src as a component of Red Hat Enterprise Linux 6 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound?arch=src

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • no fix planned: Out of support scope
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-devel as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound-devel

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-python as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound-python

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • python3-unbound as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/python3-unbound

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-devel as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound-devel

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound.src as a component of Red Hat Enterprise Linux 8 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound?arch=src

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound-dracut as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound-dracut

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • unbound.src as a component of Red Hat Enterprise Linux 9 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/unbound?arch=src

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00
  • openshift/ose-rhel-coreos-9 as a component of Red Hat OpenShift Container Platform 4 · known affected

    Vendor assessment for this product only.

    pkg:oci/[email protected]?repository_url=registry.redhat.io/openshift/ose-rhel-coreos-9

    • workaround: To mitigate this issue, restrict network access to the Unbound DNS resolver to only trusted clients and networks. This can be achieved by configuring firewall rules to limit inbound connections to the Unbound service ports (e.g., TCP port 53 for DNS over TCP, TCP port 853 for DNS over TLS). For example, using `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="53" protocol="tcp" accept'` and `firewall-cmd --permanent --add-rich-rule='rule family="ipv4" source address="<TRUSTED_NETWORK>" port port="853" protocol="tcp" accept'`. After adding rules, apply them with `firewall-cmd --reload`. Replace `<TRUSTED_NETWORK>` with the IP address or network range of trusted clients. Reloading firewall rules may temporarily interrupt network connections.
    • none available: Fix deferred
    Red Hat · CVE-2026-80225 · Updated 2026-09-23T20:29:52+00:00

Known Affected Software Configurations

VendorProductVersion range
NlnetlabsUnbound< 1.26.1

All CVSS metrics

  • MEDIUM 5.3 v3.1 · CNA Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
  • MEDIUM 5.3 v3.1 · NVD Secondary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
  • HIGH 7.5 v3.1 · NVD Primary
    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Patches & mitigations

Advisories

Technical & other

Sources: NVD · CVE.org · EPSS