CVE-2025-40779 - CVE House
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Status published High CVE-2025-40779

Kea crash upon interaction between specific client options and subnet selection

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • ISC would like to thank the following for bringing this vulnerability to our attention: * Jochen M. * Martin Dinev, Trading212 * Ashwani Kumar, Post Graduate Institute of Medical Education & Research, Chandigarh, India * Bret Giddings, University of Essex * Florian Ritterhoff, Munich University of Applied Sciences

Affected Vendor

Affected Software

Kea
Vulnerable Versions:
2.7.1, 3.0.0, 3.1.0, 2.6.0

Timeline

Official Publish: August 27th, 2025
Last Modified: November 4th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weaknesses (CWE)