What is CVE-2026-13321?

CVE-2026-13321 is a high-severity vulnerability in Isc Bind 9, classified under Origin Validation Error. CVSS score: 8.6/10. Published 2026-07-22.

How severe is CVE-2026-13321?

High severity. CVSS v3 base score is 8.6 out of 10.

Vulnerability in Isc Bind 9

CVE-2026-13321

The BIND resolver accepts validly-signed NSEC records where the "Next Domain Name" field points outside the signer's zone. 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…

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N.

Affected products

Isc Bind 9 — versions 9.11.0, 9.20.0, 9.21.0

Weakness classification (CWE)

CWE-346 — Origin Validation Error

References

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

Frequently asked questions

What is CVE-2026-13321?: CVE-2026-13321 is a high-severity vulnerability in Isc Bind 9, classified under Origin Validation Error. CVSS score: 8.6/10. Published 2026-07-22.
How severe is CVE-2026-13321?: High severity. CVSS v3 base score is 8.6 out of 10.