CVE-2025-40779

Kea crash upon interaction between specific client options and subnet selection

Description

If a DHCPv4 client sends a request with some specific options, and Kea fails to find an appropriate subnet for the client, the `kea-dhcp4` process will abort with an assertion failure. This happens only if the client request is unicast directly to Kea; broadcast messages do not cause the problem. This issue affects Kea versions 2.7.1 through 2.7.9, 3.0.0, and 3.1.0.

Remediation

Solution:

  • Upgrade to the patched release most closely related to your current version of Kea: 3.0.1 or 3.1.1.

Workaround:

  • No workarounds known.

Category

7.5
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.02%
Vendor Advisory isc.org
Affected: ISC Kea
Published at:
Updated at:

References

Link Tags
https://kb.isc.org/docs/cve-2025-40779 vendor advisory

Frequently Asked Questions

What is the severity of CVE-2025-40779?
CVE-2025-40779 has been scored as a high severity vulnerability.
How to fix CVE-2025-40779?
To fix CVE-2025-40779: Upgrade to the patched release most closely related to your current version of Kea: 3.0.1 or 3.1.1.
Is CVE-2025-40779 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2025-40779 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2025-40779?
CVE-2025-40779 affects ISC Kea.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.