CVE-2026-34000: redhat enterprise_linux Out-of-bounds Read

Vulnerability summary

CVE-2026-34000 is a critical (CVSS 9.1) Out-of-bounds Read vulnerability in redhat enterprise_linux. EPSS estimates a 0.53% chance of exploitation in the next 30 days, higher than 43.3% of scored vulnerabilities.

Timeline

1. 05-05-2026
   PublishedVulnerability first disclosed.
2. 08-06-2026
   Last modifiedVulnerability information updated.

Description

A flaw was found in the X.Org X server. This out-of-bounds read vulnerability in the XKB geometry processing, specifically within the `CheckSetGeom()` and `XkbAddGeomKeyAlias` functions, allows an attacker to read uninitialized or out-of-bounds memory. An attacker with a connection to the X11 server, either locally or remotely, can exploit this without user interaction. This could lead to the disclosure of memory contents or cause a denial of service by crashing the server.

• CWE-125Out-of-bounds ReadThe product reads data past the end, or before the beginning, of the intended buffer.