CVE-2026-25704 Incomplete privilege drop for com.system76.CosmicGreeter.GetUserData
An attacker can exploit a race condition in cosmic-greeter to regain dropped privileges and escalate their access rights.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-25704?
CVE-2026-25704 is a medium-severity vulnerability in pop-os cosmic-greeter, published on 30 Mar 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A Privilege Dropping / Lowering Errors/Time-of-check Time-of-use (TOCTOU) Race Condition vulnerability in cosmic-greeter can allow an attacker to regain privileges that should have been dropped and abuse them in the racy checking logic.
This issue affects cosmic-greeter before https://github.Com/pop-os/cosmic-greeter/pull/426.
Which versions are affected by CVE-2026-25704?
How do I fix CVE-2026-25704?
No fix has been published for CVE-2026-25704 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-25704 being exploited?
There is no known exploitation of CVE-2026-25704 in the wild and no public exploit code.
Sources
Also known as GHSA-h5vx-6jh5-qhq7.