Vulnerability · Published Aug 27, 2025 · Assigned by isc
CVE-2025-40779Kea crash upon interaction between specific client options and subnet selection
High 7.5
In plain English
A high-severity null pointer dereference in Kea from ISC. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 46% of all known vulnerabilities).
Severity (CVSS 3.1)7.5High
Exploit odds (30 days)0.5%top 54.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | isc-kea | no fix listed | CVE-2025-40779 |
| Debian:13 | isc-kea | no fix listed | CVE-2025-40779 |
| Debian:14 | isc-kea | no fix listed | CVE-2025-40779 |
| Ubuntu:22.04:LTS | isc-kea | no fix listed | UBUNTU-CVE-2025-40779 |
| Ubuntu:24.04:LTS | isc-kea | no fix listed | UBUNTU-CVE-2025-40779 |
| Ubuntu:25.10 | isc-kea | no fix listed | UBUNTU-CVE-2025-40779 |
Affected products (as reported)
Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H