PT-2026-46936 · Red Hat · Red Hat Enterprise Linux 10+4

Published 2026-06-05 · Updated 2026-06-05 · CVE-2026-50256

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. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but libXfont2's alias target name length is 1024 bytes. A font alias name between 257 and 1023 bytes causes the X server to copy that name into the undersized stack buffer without further checks. 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-2026-50256

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-2026-50256 · Security Note
• https://bugzilla.redhat.com/show_bug.cgi?id=2485380 · Note
• https://gitlab.freedesktop.org/xorg/xserver/-/commit/bb5158f962dc935e58ef8b4b5fcb31be201a6e07 · Note
• https://redhat.atlassian.net/browse/PSIRTSUPT-16950 · Note
• https://lists.x.org/archives/xorg-announce/2026-June/003702.html · Note
• https://access.redhat.com/security/cve/CVE-2026-50256 · Note