CVE-2025-49178 Xorg-x11-server-xwayland: xorg-x11-server: tigervnc: unprocessed client request due to bytes to ignore
A flaw in X server request handling allows attackers to cause denial of service by skipping processing of other client requests.
- 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-2025-49178?
CVE-2025-49178 is a medium-severity denial of service 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 X server's request handling. Non-zero 'bytes to ignore' in a client's request can cause the server to skip processing another client's request, potentially leading to a denial of service.
Weakness: CWE-667
Which versions are affected by CVE-2025-49178?
How do I fix CVE-2025-49178?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-49178 being exploited?
There is no known exploitation of CVE-2025-49178 in the wild and no public exploit code.
Sources
Also known as AZL-64202, AZL-64230, AZL-64259, BELL-CVE-2025-49178, CLSA-2025-1757662405, CLSA-2025-1757666519 and 3 more.