CVE-2026-13204

Description

If a provably insecure domain is covered by both an NSEC and NSEC3 record at the parent, and there exist an RRSIG for only one of these types, then BIND may exit unexpectedly with an assertion while validating this proof. This issue affects BIND 9 versions 9.11.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.11.3-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
bind9	26.10 stonking	Not affected
	26.04 LTS resolute	Fixed in 1:9.20.24-1ubuntu0.3
	24.04 LTS noble	Fixed in 1:9.18.39-0ubuntu0.24.04.7
	22.04 LTS jammy	Fixed in 1:9.18.39-0ubuntu0.22.04.6
	20.04 LTS focal	Fixed in 1:9.18.30-0ubuntu0.20.04.2+esm3
	18.04 LTS bionic	Fixed in 1:9.11.3+dfsg-1ubuntu1.19+esm6
	16.04 LTS xenial	Fixed in 1:9.10.3.dfsg.P4-8ubuntu1.19+esm11
	14.04 LTS trusty	Fixed in 1:9.9.5.dfsg-3ubuntu0.19+esm15
isc-dhcp	26.10 stonking	Not in release
	26.04 LTS resolute	Needs evaluation
	24.04 LTS noble	Needs evaluation
	22.04 LTS jammy	Not affected
	20.04 LTS focal	Not affected
	18.04 LTS bionic	Needs evaluation
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
bind9-libs	26.10 stonking	Not in release
	26.04 LTS resolute	Not in release
	24.04 LTS noble	Not in release
	22.04 LTS jammy	Needs evaluation
	20.04 LTS focal	Needs evaluation

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Notes

alexmurray

As of isc-dhcp-4.4.3-1, isc-dhcp vendors bind9 libs

mdeslaur

in focal and jammy, isc-dhcp uses the bind9-libs package This is unlikely to affect isc-dhcp's use of bind9-libs and the vendored bind9 libs, marking as negligible

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
bind9	Upstream: 0cf010c Upstream: 6c0e599 Upstream: 48f5aa5 Upstream: 204fde8

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	None
Availability impact	High

Scores

Parameter	Value
Base score	7.5 · High
Exploitability score	-
Impact score	-

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

References

Related Ubuntu Security Notices (USN)

USN-8696-1
Bind vulnerability
31 August 2026

USN-8929-1
Bind vulnerabilities
14 October 2026