CVE-2026-13321: ISC BIND 9

High severity, CVSS 8.6. EPSS: 0.2% chance of exploitation in the next 30 days.

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 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.

Affected products

• ISC BIND 9: from 9.11.0, up to and including 9.18.50; from 9.20.0, up to and including 9.20.24; from 9.21.0, up to and including 9.21.23; from 9.11.3-S1, up to and including 9.18.50-S1; from 9.20.9-S1, up to and including 9.20.24-S1

Published 2026-07-22. Last modified 2026-07-22.