What is CVE-2026-29111?

CVE-2026-29111 is a medium-severity vulnerability in Systemd, classified under Improper Privilege Management. CVSS score: 5.5/10. Published 2026-03-23.

How severe is CVE-2026-29111?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Privilege escalation in Systemd

CVE-2026-29111

systemd, a system and service manager, (as PID 1) hits an assert and freezes execution when an unprivileged IPC API call is made with spurious data. On version v249 and older the effect is not an assert, but stack overwriting, with the attacker controlled content. From version v250 and newer this is not possible as the safety check causes an assert instead. This IPC call was added in v239, so versions older than that are not affected. Versions 260-rc1, 259.2, 258.5, and 257.11 contain patches. No known workarounds are available.

Vulnerability class: Privilege Escalation

Published 2026-03-23 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (6.3th percentile), scored 2026-10-23.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 6th percentile — 6.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.002 · change: +0.001

Affected products

Systemd — versions >= 239, < 257.11, >= 258, < 258.5, >= 259, < 259.2
Systemd Project

Weakness classification (CWE)

CWE-269 — Improper Privilege Management

References

Frequently asked questions

What is CVE-2026-29111?: CVE-2026-29111 is a medium-severity vulnerability in Systemd, classified under Improper Privilege Management. CVSS score: 5.5/10. Published 2026-03-23.
How severe is CVE-2026-29111?: Medium severity. CVSS v3 base score is 5.5 out of 10.