CVE-2026-81563

EUVD-2026-80770

16.09.2026, 14:17

A BIND resolver encountering an SVCB/HTTPS AliasMode record referencing 14 or more SVCB/HTTPS ServiceMode records may fail to properly deallocate internal resources. If this happens repeatedly, resource exhaustion will eventually prevent the resolver from performing new recursive lookups.
This issue affects BIND 9 versions 9.18.0 through 9.18.50, 9.20.0 through 9.20.27, 9.21.0 through 9.21.25, 9.18.11-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.27-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
forky	vulnerable
sid	1:9.20.29-1 fixed
trixie	vulnerable
trixie (security)	vulnerable

Common Weakness Enumeration

CWE-401 - Missing Release of Memory after Effective Lifetime
The software does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory.

References

https://downloads.isc.org/isc/bind9/9.20.29

https://downloads.isc.org/isc/bind9/9.21.26

https://kb.isc.org/docs/cve-2026-81563