CVE-2026-56003

High

Description

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.

SeverityHigh

CVSS8.5

Exploit probability—

ProductLibxfont

PublishedJul 8, 2026

First seenJul 8, 2026

Weakness typeCWE-122CWE-122

How to fix

Update

x libxfont2.0.8 or later

Patches

gitlab.freedesktop.org/xorg/lib/libxfont/-/commit/dff957a5158da038a282a59a31fe736702732939

Vendor advisories

openwall.com/lists/oss-security/2026/07/08/1

Affected products

Product	Affected versions	Fixed in
x libxfont	2.0.0 ≤ v < 2.0.8	2.0.8

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