CVE-2026-11622

Potential memory usage beyond configured limits

State: Published
Severity: 7.5 High
Published: Jul 22, 2026
Updated: Jul 22, 2026
Reserved: Jun 8, 2026

Description

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.

Scores

CVSS	Score	Vector	Source
3.1	7.5 High	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H	isc

Weaknesses

CWE-770 Allocation of Resources Without Limits or Throttling

Affected Products

Product	Versions
BIND 9ISC	9.11.0 through 9.18.50Affected 9.20.0 through 9.20.24Affected 9.21.0 through 9.21.23Affected 9.11.3-S1 through 9.18.50-S1Affected 9.20.9-S1 through 9.20.24-S1Affected

References

CVE-2026-11622vendor-advisory
https://downloads.isc.org/isc/bind9/9.20.26patch
https://downloads.isc.org/isc/bind9/9.21.24patch

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