CVE-2026-34003 Xorg: xwayland: x.org x server: information exposure and denial of service via out-of-bounds memory access
A local attacker can trigger out-of-bounds memory access in the X.Org X server, leading to information disclosure or denial of service.
- 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-2026-34003?
CVE-2026-34003 is a high-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 23 Apr 2026. 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.Org X server's XKB key types request validation. A local attacker could send a specially crafted request to the X server, leading to an out-of-bounds memory access vulnerability. This could result in the disclosure of sensitive information or cause the server to crash, leading to a Denial of Service (DoS). In certain configurations, higher impact outcomes may be possible.
Weakness: CWE-125
Which versions are affected by CVE-2026-34003?
How do I fix CVE-2026-34003?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-34003 being exploited?
There is no known exploitation of CVE-2026-34003 in the wild and no public exploit code.
Sources
Also known as AZL-84633, AZL-84845, BELL-CVE-2026-34003, DEBIAN-CVE-2026-34003, ECHO-d72b-8ceb-b726, GHSA-5mqr-3465-c7p6 and 1 more.