Vulnerability DatabaseCVE-2026-55999
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CVE-2026-55999
Published:July 08, 2026
Updated:July 21, 2026
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.
Affected Packages
https://gitlab.freedesktop.org/xorg/xserver.git (SCM_GIT):
Affected version(s) >=xorg-server-1.1.1 <xorg-server-21.1.24
Fix Suggestion:
Update to version xorg-server-21.1.24
https://gitlab.freedesktop.org/xorg/xserver.git (SCM_GIT):
Affected version(s) >=xwayland-21.0.99.901 <xwayland-24.1.13
Fix Suggestion:
Update to version xwayland-24.1.13
Related Resources (2)
https://www.openwall.com/lists/oss-security/2026/07/08/2
https://gitlab.freedesktop.org/xorg/xserver/-/commit/fbf7bac22e2c6bd627fb042742a23318263edae1
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CVSS v4
Base Score:
9
Attack Vector
NETWORK
Attack Complexity
HIGH
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
HIGH
Subsequent System Integrity
HIGH
Subsequent System Availability
HIGH
CVSS v3
Base Score:
8.5
Attack Vector
NETWORK
Attack Complexity
HIGH
Privileges Required
LOW
User Interaction
NONE
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Heap-based Buffer Overflow
CWE-122
EPSS
Base Score:
0.21