Description
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.
Published: 2026-09-16
Score: 7.5 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

Vendor Solution

Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.29, 9.21.26, or 9.20.29-S1.


Vendor Workaround

No workarounds known.

Tracking

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Advisories
Source ID Title
Debian DSA Debian DSA DSA-6505-1 bind9 security update
History

Thu, 17 Sep 2026 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Thu, 17 Sep 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-617
References
Metrics threat_severity

None

threat_severity

Important


Wed, 16 Sep 2026 14:30:00 +0000

Type Values Removed Values Added
Description 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.
Title Use-after-free in query_addnoqnameproof() via the DNS64 filter64 path
First Time appeared Isc
Isc bind
Weaknesses CWE-416
CPEs cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
Vendors & Products Isc
Isc bind
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: isc

Published:

Updated: 2026-09-17T17:38:45.420Z

Reserved: 2026-08-12T20:26:23.829Z

Link: CVE-2026-19666

cve-icon Vulnrichment

Updated: 2026-09-17T17:38:41.163Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-16T15:17:33.520

Modified: 2026-09-17T18:16:39.403

Link: CVE-2026-19666

cve-icon Redhat

Severity : Important

Publid Date: 2026-09-16T14:02:30Z

Links: CVE-2026-19666 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-17T09:15:12Z

Weaknesses