CVE-2025-40778: ISC BIND 9

High severity, CVSS 8.6. EPSS: 0.7% chance of exploitation in the next 30 days.

Under certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.

Affected products

• ISC BIND 9: from 9.11.0, up to and including 9.16.50; from 9.18.0, up to and including 9.18.39; from 9.20.0, up to and including 9.20.13; from 9.21.0, up to and including 9.21.12; from 9.11.3-S1, up to and including 9.16.50-S1; from 9.18.11-S1, up to and including 9.18.39-S1; …

Published 2025-10-22. Last modified 2026-10-08.