CVE-2026-55999
highCVSS v3 Base Score
7.5
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score
0.3%
Exploitation probability in 30 days
Top 80% most likely to be exploited
Attack Characteristics
Attack Vector
Network
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Confidentiality
High
Integrity
High
Availability
High
Vulnerability Report
Generated by CyberWatcher
Description
A flaw was found in the glamor_font_get() function of the xorg-x11-server. This vulnerability, a heap buffer overflow, occurs when the server processes a specially crafted PCF font file where individual glyph metrics exceed the declared maximum bounds. An authenticated X client can exploit this by loading a malicious font and drawing text, potentially leading to arbitrary code execution with attacker-controlled content and extent. This affects servers utilizing the glamor acceleration backend, such as Xorg with the modesetting driver and Xwayland.
CWE
CWE-805Affected Products
Red Hat Enterprise Linux 10Red Hat Enterprise Linux 6Red Hat Enterprise Linux 7Red Hat Enterprise Linux 8Red Hat Enterprise Linux 9