---
id: "CVE-2026-94300"
kind: "vulnerability"
aliases: ["CVE-2026-94300"]
title: "BIND named: replayed GSS-TSIG UDP messages corrupt memory, possibly allowing code execution"
severity: "high"
cvss: 8.1
epss: 0.00734
exploited: false
status: "open"
category: "runtime"
products: []
ecosystems: []
tags: ["bind", "dns", "linux", "runtime", "self-hosted"]
not_affected_if: ["default-config", "non-affected-version"]
published_at: "2026-10-21T13:21:08+00:00"
first_seen_at: "2026-10-23T21:57:28+00:00"
updated_at: "2026-10-25T03:05:54+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-94300", "first_seen_at": "2026-10-23T21:57:28+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-94300", "first_seen_at": "2026-10-24T13:15:54+00:00"}]
---

# BIND named: replayed GSS-TSIG UDP messages corrupt memory, possibly allowing code execution

Replaying a captured GSS-TSIG signed UDP message to BIND's named while the TSIG key is valid corrupts memory. Combined with crafted queries to an attacker-controlled zone, this may allow remote code execution.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Run `named -V` or `named -v` and compare the version against the affected ranges: 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, 9.20.9-S1 through 9.20.29-S1.
- Check named.conf for GSS-TSIG configuration (`tkey-gssapi-keytab` or `tkey-gssapi-credential`) to see whether the feature is in use.

## Fix

- Upgrade BIND to a fixed release that is newer than the affected ranges above (the sources do not list the exact fixed version: unknown).
- Until patched, disable GSS-TSIG if it is not needed (version of the workaround: unknown).

## Timeline

- 2026-10-23T21:57:28+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-94300
- 2026-10-24T13:15:54+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-94300

## Documents

- [discussion] @_r_netsec: CVE-2026-94300: Concurrent GSS-TSIG messages corrupt memory https://t.co/0PiMKDs https://x.com/_r_netsec/status/2113315282194440566

## From the sources

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.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_