CVE-2026-56003

Severity CVSS v4.0:

Pending analysis

Type:

CWE-122 Heap-based Buffer Overflow

Publication date:

08/07/2026

Last modified:

08/07/2026

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.

Impact

Vector 3.x

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H CVSS v3.1 Severity and Metrics:

Base Score: 8.50 HIGH
Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

Attack Vector (AV): Network
Attack Complexity (AC): High
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Changed
Confidentiality (C): High
Integrity (I): High
Availability (A): High

Base Score 3.x

8.50

Severity 3.x

HIGH

References to Advisories, Solutions, and Tools

https://gitlab.freedesktop.org/xorg/lib/libxfont/-/commit/dff957a5158da038a282a59a31fe736702732939
https://www.openwall.com/lists/oss-security/2026/07/08/1