CVE-2026-13204

Unexpected exit in certain situations with NSEC and NSEC3 both present

State: Published
Severity: 7.5 High
Published: Jul 22, 2026
Updated: Jul 22, 2026
Reserved: Jun 24, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	isc

Weaknesses

CWE-617 Reachable Assertion

Affected Products

Product	Versions
BIND 9ISC	9.11.0 through 9.18.50Affected 9.20.0 through 9.20.24Affected 9.21.0 through 9.21.23Affected 9.11.3-S1 through 9.18.50-S1Affected 9.20.9-S1 through 9.20.24-S1Affected

References

CVE-2026-13204vendor-advisory
https://downloads.isc.org/isc/bind9/9.20.26patch
https://downloads.isc.org/isc/bind9/9.21.24patch

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