CVE-2025-26596: Red Hat Enterprise Linux

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.

Affected products

• Red Hat Enterprise Linux: version 7.0 only; version 8.0 only; version 9.0 only
• Tigervnc Tigervnc: affected versions not specified
• X.org X Server: before 21.1.16 (fixed in 21.1.16)
• X.org Xwayland: before 24.1.6 (fixed in 24.1.6)

Published 2025-02-25. Last modified 2026-06-29.