Replaying GSS-TSIG signed UDP messages can result in memory corruption in "`named`". An attacker who can capture a previously signed UDP message can replay it while the negotiated TSIG key is still valid. By also sending crafted queries to a zone the attacker controls, the attacker may potentially achieve remote code execution.
This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1.

Project Subscriptions

Vendors Products
Advisories
Source ID Title
Debian DSA Debian DSA DSA-6576-1 bind9 security update
Fixes

Solution

Upgrade to the patched release most closely related to your current version of BIND 9: 9.20.30, 9.21.27, or 9.20.30-S1.


Workaround

No workarounds known.

History

Wed, 21 Oct 2026 13:00:00 +0000

Type Values Removed Values Added
Description Replaying GSS-TSIG signed UDP messages can result in memory corruption in "`named`". An attacker who can capture a previously signed UDP message can replay it while the negotiated TSIG key is still valid. By also sending crafted queries to a zone the attacker controls, the attacker may potentially achieve remote code execution. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.29, 9.21.0 through 9.21.26, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.29-S1.
Title Concurrent GSS-TSIG messages corrupt memory
First Time appeared Isc
Isc bind
Weaknesses CWE-362
CWE-415
CPEs cpe:2.3:a:isc:bind:*:*:*:*:*:*:*:*
Vendors & Products Isc
Isc bind
References
Metrics cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: isc

Published:

Updated: 2026-10-21T17:19:14.274Z

Reserved: 2026-09-21T09:46:27.369Z

Link: CVE-2026-94300

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-21T13:21:08.670

Modified: 2026-10-21T18:17:31.860

Link: CVE-2026-94300

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-21T19:15:16Z

Weaknesses