CVE-2025-40775

Name: CVE-2025-40775
Creator: NVD / NIST
Published: 2025-05-21T13:16:02.623+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.5/10EPSS 10.75%

Last modified Jun 17, 2026

CVE-2025-40775 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. 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.. EPSS estimates a 10.75% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

10.75%

95.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-232

References

Timeline

Published: May 21, 2025
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2025-40775?

How severe is CVE-2025-40775?

CVE-2025-40775 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 10.75% probability of exploitation in the next 30 days.

How do I fix CVE-2025-40775?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2025-40775?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST