CVE-2026-11622

EUVD-2026-47708

22.07.2026, 15:16

A DNSSEC validating resolver that is under a random subdomain attack against a DNSSEC-signed zone can suffer from runaway memory usage. The attacker needs to be able to send queries faster than the resolver can perform validation. The increased memory usage can be orders of magnitude beyond the limit configured in the `max-cache-size` parameter.
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.

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-770 - Allocation of Resources Without Limits or Throttling
The software allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor.

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-2026-11622