PT-2026-46938 · Red Hat · Red Hat Enterprise Linux 10+4

Published 2026-06-05 · Updated 2026-06-05 · CVE-2026-50258

Mitre

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. The X server has multiple stack buffers sized XkbMaxShiftLevel * XkbNumKbdGroups but CheckKeyTypes() does not verify or clamp non-canonical key types to XkbMaxShiftLevel. A client can change key types to excessive shift levels and trigger stack overflows. This is caused by an incomplete fix of CVE-2025-26597. This may be used to crash the server, or for privilege escalation if the X server runs as root.

Fix

Stack Overflow

Weakness Enumeration

CWE-121

Related Identifiers

CVE-2026-50258

Affected Products

Red Hat Enterprise Linux 10

Red Hat Enterprise Linux 6

Red Hat Enterprise Linux 7

Red Hat Enterprise Linux 8

Red Hat Enterprise Linux 9

References · 6

• https://nvd.nist.gov/vuln/detail/CVE-2026-50258 · Security Note
• https://access.redhat.com/security/cve/CVE-2026-50258 · Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2485383 · Note
• https://gitlab.freedesktop.org/xorg/xserver/-/commit/543e108516428fc8c3bea91d6563ad266f9a801e · Note
• https://redhat.atlassian.net/browse/PSIRTSUPT-16950 · Note
• https://lists.x.org/archives/xorg-announce/2026-June/003702.html · Note