Heap-based Buffer Overflow Affecting xorg-server package, versions <2:21.1.16-1.3+deb13u3+e4


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.33% (24th percentile)

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  • Snyk IDSNYK-ECHOLATEST-XORGSERVER-18751942
  • published13 Aug 2026
  • disclosed8 Jul 2026

Introduced: 8 Jul 2026

CVE-2026-55999  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade Echo:latest xorg-server to version 2:21.1.16-1.3+deb13u3+e4 or higher.

NVD Description

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

Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks.

CVSS Base Scores

version 3.1