CVE-2026-50045
MEDIUM 5.3 ALL-YEARSIn NLnet Labs Unbound 1.22.0 up to and including 1.25.1, a single client query for a deeply nested name under a DNSSEC-signed parent can cause Unbound to send more upstream packets per client query than the configured 'max-global-quota'. This effectively bypasses a security configuration that limits upstream amplification traffic.
No known exploitation, public exploit, or elevated probability at this time. Track for changes.
Exploitation likelihood
0.5%chance of exploitation in 30 days · 40th percentile
Impact if exploited
5.3CVSS 3.1 · MEDIUM · CNA
- 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.
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Tracked sources are checked weekly for the full archive, including PoCs published after the original disclosure. A later release appears after a tracked source lists it and a refresh succeeds.
Weakness (CWE)
- CWE-406: : Insufficient Control of Network Message Volume (Network Amplification)
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 35 vendor product statements; 3 omitted. Read the full vendor advisory.
unbound-main@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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
unbound-main@noarch 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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
unbound-main@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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
unbound-main@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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
unbound as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/unbound
- workaround: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
unbound-devel as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/unbound-devel
- workaround: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
unbound-libs as a component of Red Hat Enterprise Linux 10 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/unbound-libs
- workaround: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
python3-unbound as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/python3-unbound
- workaround: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
unbound as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/unbound
- workaround: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
unbound-devel as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/unbound-devel
- workaround: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
unbound-libs as a component of Red Hat Enterprise Linux 9 · known affected
Vendor assessment for this product only.
pkg:rpm/redhat/unbound-libs
- workaround: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
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: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
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/ose-rhel-coreos-9?repository_url=registry.redhat.io/openshift/ose-rhel-coreos-9
- workaround: Restrict recursive DNS access strictly to trusted networks using firewall access controls, reloading the service to apply changes. Additionally, configure Rate Limiting on outbound traffic to throttle anomalous spikes and mitigate amplification risks.
- none available: Fix deferred
unbound as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound-devel as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound-devel
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound-libs as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound-libs
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound-python as a component of Red Hat Enterprise Linux 6 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound-python
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound-devel as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound-devel
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound-libs as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound-libs
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound-python as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound-python
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound.src as a component of Red Hat Enterprise Linux 7 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound?arch=src
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00python3-unbound as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/python3-unbound
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound-devel as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound-devel
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound-libs as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound-libs
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00unbound.src as a component of Red Hat Enterprise Linux 8 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:rpm/redhat/unbound?arch=src
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00openshift/ose-rhel-coreos-8 as a component of Red Hat OpenShift Container Platform 4 · known not affected
Vendor assessment for this product only.
Reason: vulnerable code not present
pkg:oci/ose-rhel-coreos-8?repository_url=registry.redhat.io/openshift/ose-rhel-coreos-8
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00
Known Affected Software Configurations
| Vendor | Product | Version range |
|---|---|---|
| Nlnetlabs | Unbound | ≥ 1.22.0 and < 1.25.2 |
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
References
Advisories
- https://www.nlnetlabs.nl/downloads/unbound/CVE-2026-50045.txt CVE record · NLnet Labs · Updated 2026-07-22T13:07:55.730Z
NVD · CVE-2026-50045 · Updated 2026-10-24T13:10:00.147
Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00 - https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50045.json Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00
- https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-47671 EUVD · EUVD-2026-47671
Technical & other
- https://access.redhat.com/security/cve/CVE-2026-50045 Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00
- https://bugzilla.redhat.com/show_bug.cgi?id=2506136 Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00
- https://www.cve.org/CVERecord?id=CVE-2026-50045 Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00
- https://nvd.nist.gov/vuln/detail/CVE-2026-50045 Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00
- https://access.redhat.com/errata/RHSA-2026:43588 Red Hat · CVE-2026-50045 · Updated 2026-08-31T11:33:54+00:00
Sources: NVD · CVE.org · All sources and attribution · EPSS