How severe is CVE-2025-40778?

CVE-2025-40778 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2025-40778 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-40778?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2025-40778 have an EU (EUVD) identifier?

Yes. CVE-2025-40778 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-35581.

When was CVE-2025-40778 published?

CVE-2025-40778 was published on 2025-10-22 and last updated on 2026-06-17.

CVE-2025-40778

CVE-2025-40778 is a high-severity vulnerability with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-349.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 1% (40th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-35581
Weakness: CWE-349
Published: 2025-10-22
Last modified: 2026-06-17

Description

Under certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.

Frequently asked questions

What is CVE-2025-40778?: Under certain circumstances, BIND is too lenient when accepting records from answers, allowing an attacker to inject forged data into the cache. This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.39, 9.20.0 through 9.20.13, 9.21.0 through 9.21.12, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.39-S1, and 9.20.9-S1 through 9.20.13-S1.
How severe is CVE-2025-40778?: CVE-2025-40778 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2025-40778 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (40th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-40778?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2025-40778 have an EU (EUVD) identifier?: Yes. CVE-2025-40778 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-35581.
When was CVE-2025-40778 published?: CVE-2025-40778 was published on 2025-10-22 and last updated on 2026-06-17.

References

Other CWE-349 vulnerabilities

CVE-2026-42960 — Critical (CVSS 10.0): NLnet Labs Unbound up to and including version 1.25.0 is vulnerable to poisoning via promiscuous records for the…
CVE-2026-41120 — Critical (CVSS 9.8): Dell Wyse Management Suite, versions prior to WMS 5.5 HF1, contain an Acceptance of Extraneous Untrusted Data With…
CVE-2026-45602 — Critical (CVSS 9.1): No cwe for this issue in Windows DHCP Server allows an unauthorized attacker to perform tampering over a network.
CVE-2025-5994 — High (CVSS 8.7): A multi-vendor cache poisoning vulnerability named 'Rebirthday Attack' has been discovered in caching resolvers that…
CVE-2025-40776 — High (CVSS 8.6): A `named` caching resolver that is configured to send ECS (EDNS Client Subnet) options may be vulnerable to a…
CVE-2026-32162 — High (CVSS 8.4): Acceptance of extraneous untrusted data with trusted data in Windows COM allows an unauthorized attacker to elevate…

Browse all CWE-349 vulnerabilities →