CVE-2026-29111Public exploit

PID 1 freeze via malformed cgroup path

Published Mar 23, 2026 · Updated Mar 23, 2026

Improper input validation in affected systemd releases allows local users to freeze PID 1 through a crafted D-Bus cgroup path. The GetUnitByControlGroup method passes an attacker-sized, non-normalized path into manager_get_unit_by_cgroup without first requiring an absolute normalized path, leading newer releases to an assertion. An unprivileged local account is sufficient; upstream affected ranges are 239 through 257.10, 258 through 258.4, and 259 through 259.1, while 249 and earlier overwrite stack data instead of asserting.

CVSS severity5.5
Medium
EPSS probability0.12%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper input validation in affected systemd releases allows local users to freeze PID 1 through a crafted D-Bus cgroup path. The GetUnitByControlGroup method passes an attacker-sized, non-normalized path into manager_get_unit_by_cgroup without first requiring an absolute normalized path, leading newer releases to an assertion. An unprivileged local account is sufficient; upstream affected ranges are 239 through 257.10, 258 through 258.4, and 259 through 259.1, while 249 and earlier overwrite stack data instead of asserting.

The record

CVE
CVE-2026-29111
Published
Mar 23, 2026
Updated
Mar 23, 2026
Vendor
systemd
Product
systemd
Classifications
CWE-269, T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 23, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 23, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 239, < 257.11
  2. Affected versionversion=>= 258, < 258.5
  3. Affected versionversion=>= 259, < 259.2

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

systemd · systemdversion=>= 239, < 257.11; version=>= 258, < 258.5; version=>= 259, < 259.2

Published CVSS scores

5.5GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo