Kea DHCPv4 Unicast Assertion Failure (2.7.1-2.7.9, 3.0.0, 3.1.0)
CVE-2025-40779 Published on August 27, 2025
Kea crash upon interaction between specific client options and subnet selection
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.
Vulnerability Analysis
CVE-2025-40779 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
NULL Pointer Dereference
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. NULL pointer dereference issues can occur through a number of flaws, including race conditions, and simple programming omissions.
Products Associated with CVE-2025-40779
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Affected Versions
ISC Kea:- Version 2.7.1, <= 2.7.9 is affected.
- Version 3.0.0 is affected.
- Version 3.1.0 is affected.
- Version 2.6.0, <= 2.6.4 is unaffected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.