Executive brief
LACT is a Linux tool for GPU configuration and monitoring that uses Polkit for privilege escalation checks. An authentication bypass in how it validates process identity allows an unprivileged local attacker to perform privileged operations without proper authorization, potentially enabling unauthorized GPU reconfiguration or system compromise.
Technical details
The vulnerability is an authentication bypass in Polkit's UnixProcessSubject handling, specifically in how LACT validates the peer process ID (PID) for authorization decisions. An attacker with local access can exploit improper PID-based authentication to bypass Polkit authorization checks and execute privileged operations. The flaw affects LACT through version 0.10.0 and has been patched by commit d0478fe42c2219454e272f96b1cbd29ab37ee566. The attack requires local network access but no special privileges or user interaction.
Affected products
- ilya-zlobintsev LACT through 0.10.0
Timeline
- 2026-08-25: disclosed
- 2026-08-25: patched: commit d0478fe42c2219454e272f96b1cbd29ab37ee566