CVE-2026-55999
Received Received - Intake

Heap Buffer Overflow in Xorg Server via SetFont

Publication date: 2026-07-08

Last updated on: 2026-07-08

Assigner: SUSE

Description
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 Scores

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Meta Information

Published
2026-07-08
Last Modified
2026-07-08
Generated
2026-07-08
AI Q&A
2026-07-08
EPSS Evaluated
N/A
NVD
CVE-2026-55999
EUVD
EUVD-2026-42188

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
xorg xorg-server to 21.2.24 (exc)
xorg xwayland to 24.1.13 (exc)

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-122 A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

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Executive Summary

This vulnerability exists in the xorg-server versions before 21.2.24 and xwayland versions before 24.1.13. Local attackers who have an X connection can provide PCX fonts to the X server. Due to missing glyph boundary checks in the SetFont function, this can cause a heap buffer overflow.

Impact Analysis

Exploitation of this vulnerability can lead to a heap buffer overflow, which may allow an attacker to execute arbitrary code or cause a denial of service. The CVSS score indicates a high impact on confidentiality, integrity, and availability, meaning an attacker could potentially gain control over the affected system or disrupt its normal operation.

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