CVE-2026-3104: ISC BIND

High severity, CVSS 7.5. EPSS: 1.2% chance of exploitation in the next 30 days.

A specially crafted domain can be used to cause a memory leak in a BIND resolver simply by querying this domain. This issue affects BIND 9 versions 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, and 9.20.9-S1 through 9.20.20-S1. BIND 9 versions 9.18.0 through 9.18.46 and 9.18.11-S1 through 9.18.46-S1 are NOT affected.

Affected products

• ISC BIND: from 9.20.0, before 9.20.21 (fixed in 9.20.21); from 9.21.0, before 9.21.20 (fixed in 9.21.20)

Published 2026-03-25. Last modified 2026-09-01.