CVE-2025-40779

HIGH

ISC Kea 2.7.1-2.7.9, 3.0.0, 3.1.0 - Denial of Service via DHCPv4 Unicast Request

Title source: llm

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.

References (2)

Core 2

Core References

Various Sources vendor-advisory

https://kb.isc.org/docs/cve-2025-40779

Mailing List

http://www.openwall.com/lists/oss-security/2025/08/27/1

Scores

CVSS v3 7.5

EPSS 0.0009

EPSS Percentile 25.3%

Attack Vector NETWORK

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

CISA SSVC

Vulnrichment

Exploitation none

Automatable yes

Technical Impact partial

Details

CWE

CWE-476

Status published

Products (4)

ISC/Kea 2.6.0 - 2.6.4

ISC/Kea 2.7.1 - 2.7.9

ISC/Kea 3.0.0

ISC/Kea 3.1.0

Published Aug 27, 2025

Tracked Since Feb 18, 2026