What is CVE-2026-13204?

CVE-2026-13204 is a high-severity vulnerability in Isc Bind 9, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2026-07-22.

How severe is CVE-2026-13204?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Isc Bind 9

CVE-2026-13204

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 affect…

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Isc Bind 9 — versions 9.11.0, 9.20.0, 9.21.0

Weakness classification (CWE)

CWE-617 — Reachable Assertion

References

security-officer@isc.org (vendor-advisory)
security-officer@isc.org (patch)
security-officer@isc.org (patch)

Frequently asked questions

What is CVE-2026-13204?: CVE-2026-13204 is a high-severity vulnerability in Isc Bind 9, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2026-07-22.
How severe is CVE-2026-13204?: High severity. CVSS v3 base score is 7.5 out of 10.