CVE-2025-40775
HIGHEPSS 96th pctlDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Very high risk: more likely to be exploited than 96% of all known CVEs.
References
Related Vulnerabilities
Other CWE-232 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2023-2968 | High | 7.5 | 1.5% | - | - |
| CVE-2021-34705 | Medium | 5.3 | 1.0% | - | - |
| CVE-2022-22213 | Medium | 5.9 | 0.7% | - | - |
| CVE-2023-39914 | High | 7.5 | 0.6% | - | Fix |
| CVE-2023-39915 | High | 7.5 | 0.5% | - | Fix |
| CVE-2025-20192 | High | 7.7 | 0.4% | - | - |
Common questions
How do I fix CVE-2025-40775?
Upgrade bind9 on debian 13 to 1:9.20.9-1 or later.
Is CVE-2025-40775 being actively exploited?
Not that we know of. CVE-2025-40775 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 12.4% is the estimated probability that it will be exploited in the next 30 days. That is higher than 96% of all scored CVEs.
How severe is CVE-2025-40775?
CVE-2025-40775 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2025-40775 affect?
Published advisories record a fix for bind9 (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-05-23.