CVE-2025-49177 Xorg-x11-server-xwayland: xorg-x11-server: tigervnc: data leak in xfixes extension's xfixessetclientdisconnectmode
A flaw in the XFIXES extension allows a client to read unintended memory from previous requests due to missing length validation.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-49177?
CVE-2025-49177 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 17 Jun 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw was found in the XFIXES extension. The XFixesSetClientDisconnectMode handler does not validate the request length, allowing a client to read unintended memory from previous requests.
Weakness: CWE-200
Which versions are affected by CVE-2025-49177?
How do I fix CVE-2025-49177?
Apply the vendor's patch.
Is CVE-2025-49177 being exploited?
There is no known exploitation of CVE-2025-49177 in the wild and no public exploit code.
Sources
Also known as AZL-64271, BELL-CVE-2025-49177, DEBIAN-CVE-2025-49177, GHSA-pw35-9xmg-v8xw, UBUNTU-CVE-2025-49177.