Heap-based Buffer Overflow Affecting libxfont package, versions <1:2.0.3-1ubuntu0.20.04.1~esm2


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.4% (33rd percentile)

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  • Snyk IDSNYK-UBUNTU2004-LIBXFONT-17910078
  • published21 Jul 2026
  • disclosed8 Jul 2026

Introduced: 8 Jul 2026

CVE-2026-56003  (opens in a new tab)
CWE-122  (opens in a new tab)

How to fix?

Upgrade Ubuntu:20.04 libxfont to version 1:2.0.3-1ubuntu0.20.04.1~esm2 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libxfont package and not the libxfont package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X server.

CVSS Base Scores

version 3.1