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CVE-2026-19666

HIGH 7.5

Published 2026-09-16 · Last modified 2026-09-17

On a resolver configured to use ``dns64``, if an applicable answer from the authoritative server is malformed in a specific way, the resolver `named` process will exit unexpectedly. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-S1.

ELEVATED IMPACT

Severe if exploited (CVSS 7.5), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.6%chance of exploitation in 30 days · 47th percentile

○ In CISA KEV ○ Catalogued PoC

Impact if exploited

7.5CVSS 3.1 · HIGH

  • ConfidentialityNone
  • IntegrityNone
  • AvailabilityHigh

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

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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 Isc

Products Bind 9

Weakness (CWE)

  • CWE-416: Use After Free

CVSS vector

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

References and research data (JSON)

Vendor product assessments

Showing 32 of 508 vendor product statements; 476 omitted. Read the full vendor advisory.

  • bind-32:9.18.33-15.el10_2.12.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 10) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_2.12?arch=aarch64&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-chroot-32:9.11.36-16.el8_10.16.s390x as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10.16?arch=s390x&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-lite-devel-32:9.11.36-16.el8_10.16.x86_64 as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10.16?arch=x86_64&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-utils-32:9.11.36-16.el8_10.16.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10.16?arch=ppc64le&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind9.16-utils-debuginfo-32:9.16.23-0.22.el8_10.16.ppc64le as a component of Red Hat Enterprise Linux AppStream (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10.16?arch=ppc64le&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind9.18-32:9.18.29-14.el9_8.10.aarch64 as a component of Red Hat Enterprise Linux AppStream (v. 9) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_8.10?arch=aarch64&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-debugsource-32:9.11.36-16.el8_10.16.aarch64 as a component of Red Hat Enterprise Linux BaseOS (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10.16?arch=aarch64&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-sdb-debuginfo-32:9.11.36-16.el8_10.16.ppc64le as a component of Red Hat Enterprise Linux BaseOS (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10.16?arch=ppc64le&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind9.16-dnssec-utils-debuginfo-32:9.16.23-0.22.el8_10.16.aarch64 as a component of Red Hat Enterprise Linux CRB (v. 8) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_10.16?arch=aarch64&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-utils-debuginfo-32:9.16.23-40.el9_8.10.s390x as a component of Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) · fixed

    Vendor assessment for this product only.

    pkg:rpm/redhat/[email protected]_8.10?arch=s390x&epoch=32

    • vendor fix: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Vendor guidance
    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-utils-0:9.20.29-0.1.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, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-devel as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind-devel

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-export-libs as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind-export-libs

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-libs as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind-libs

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-license as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind-license

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-pkcs11 as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind-pkcs11

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-pkcs11-libs as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind-pkcs11-libs

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-sdb as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind-sdb

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-sdb-chroot as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind-sdb-chroot

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind.src as a component of Red Hat Enterprise Linux 7 · known affected

    Vendor assessment for this product only.

    pkg:rpm/redhat/bind?arch=src

    • workaround: To mitigate this issue, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+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, disable the `dns64` feature in the BIND resolver configuration if it is not required. This can be done by removing or commenting out the `dns64` configuration block in `named.conf` or related configuration files. After modifying the configuration, the BIND service (`named`) must be reloaded or restarted for the changes to take effect. This action may temporarily interrupt DNS resolution services.
    • none available: Affected
    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind 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/bind

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-chroot 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/bind-chroot

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-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/bind-devel

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-sdb 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/bind-sdb

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind-utils 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/bind-utils

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • bind.src 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/bind?arch=src

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • dhcp-client as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/dhcp-client

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • dhcp-relay as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/dhcp-relay

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • dhcp-server as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/dhcp-server

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00
  • dhcp.src as a component of Red Hat Enterprise Linux 9 · known not affected

    Vendor assessment for this product only.

    Reason: vulnerable code not present

    pkg:rpm/redhat/dhcp?arch=src

    Red Hat · CVE-2026-19666 · Updated 2026-10-09T03:40:23+00:00

All CVSS metrics

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