CVE-2026-11605

EUVD-2026-47707

22.07.2026, 15:16

The issue is a resource exhaustion vulnerability associated with DNSSEC validation. BIND always validates all RRSIG records in an answer, even if they are not strictly needed. A query to an authoritative server/zone which returns many valid but superfluous RRSIG records causes the validator to waste disproportionate CPU time.
This issue affects BIND 9 versions 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, and 9.20.9-S1 through 9.20.24-S1.

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	7.5 HIGH	NETWORK	LOW	NONE	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Awaiting analysis

This vulnerability is currently awaiting analysis.

Base Score

CVSS 3.x

EPSS Score

Percentile: Unknown

Debian Releases

Debian Product

Codename

bind9

bookworm	vulnerable
bookworm (security)	vulnerable
bullseye	vulnerable
bullseye (security)	vulnerable
forky	vulnerable
sid	vulnerable
trixie	vulnerable
trixie (security)	vulnerable

Common Weakness Enumeration

CWE-408 - Incorrect Behavior Order: Early Amplification
The software allows an entity to perform a legitimate but expensive operation before authentication or authorization has taken place.

References

https://downloads.isc.org/isc/bind9/9.20.26

https://downloads.isc.org/isc/bind9/9.21.24

https://kb.isc.org/docs/cve-2026-11605