CVE-2025-40775

high
Published — · Modified —
CVSS v3
CVSS v2
VIR risk
8.0

Description

When an incoming DNS protocol message includes a Transaction Signature (TSIG), BIND always checks it. If the TSIG contains an invalid value in the algorithm field, BIND immediately aborts with an assertion failure. This issue affects BIND 9 versions 9.20.0 through 9.20.8 and 9.21.0 through 9.21.7.

Predictions

Exploit likelihood
20%
Patch ETA

Heuristic predictions, AS-IS, for prioritization only.

Mitigations

vendor Authored 2026-05-27

Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2025-40775.html

vendor Authored 2026-05-27

Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2025-40775

vendor Authored 2026-05-27

Vendor advisory: arch — https://security.archlinux.org/ASA-202505-14

OS impact

OSVersionStatusFixed in
debian debianbookwormfixed0
debian debianbullseyefixed0
debian debianforkyfixed1:9.20.9-1
debian debiansidfixed1:9.20.9-1
debian debiantrixiefixed1:9.20.9-1
arch archfixed9.20.9-1
suse slesaffected

References

Verify integrity in audit chain (admin only). AS-IS.