CVE-2026-4105

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.

The Red Hat Product Security team has assessed the severity of this vulnerability as Moderate. The issue allows a local privilege escalation to root through the systemd-machined service when specific environmental conditions are met. Successful exploitation requires an unprivileged user to be logged into an active graphical desktop session on a system where systemd-machined is present. Additionally, the affected component is not typically installed by default on many systems and terminal-only or remote sessions (such as SSH) are not affected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.