Stack-based Buffer Overflow Affecting xorg-x11-server package, versions <0:1.20.11-34.el9_8.2


Severity

Recommended
0.0
high
0
10

Based on Rocky Linux security rating.

Threat Intelligence

EPSS
0.21% (12th percentile)

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  • Snyk IDSNYK-ROCKY9-XORGX11SERVER-17389145
  • published20 Jun 2026
  • disclosed5 Jun 2026

Introduced: 5 Jun 2026

NewCVE-2026-50256  (opens in a new tab)
CWE-121  (opens in a new tab)

How to fix?

Upgrade Rocky-Linux:9 xorg-x11-server to version 0:1.20.11-34.el9_8.2 or higher.
This issue was patched in RLSA-2026:26610.

NVD Description

Note: Versions mentioned in the description apply only to the upstream xorg-x11-server package and not the xorg-x11-server package as distributed by Rocky-Linux. See How to fix? for Rocky-Linux:9 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1