CVE-2026-3039: ISC BIND

High severity, CVSS 7.5. EPSS: 1% chance of exploitation in the next 30 days.

BIND servers that are configured to use TKEY-based authentication via GSS-API tokens are vulnerable to excessive memory consumption when receiving and processing maliciously-constructed packets. Typically these servers will be found in Active Directory integrated DNS deployments and/or Kerberos-secured DNS environments. This issue affects BIND 9 versions 9.0.0 through 9.16.50, 9.18.0 through 9.18.48, 9.20.0 through 9.20.22, 9.21.0 through 9.21.21, 9.9.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.48-S1, and 9.20.9-S1 through 9.20.22-S1.

Affected products

• ISC BIND: from 9.0.0, up to and including 9.16.50; from 9.18.0, before 9.18.49 (fixed in 9.18.49); from 9.20.0, before 9.20.23 (fixed in 9.20.23); from 9.21.0, before 9.21.22 (fixed in 9.21.22)

Published 2026-05-20. Last modified 2026-09-17.