8.5

CVE-2026-55999

xorg-server / xwayland glamor font atlas Heap Buffer Overflow

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.
Daten sind bereitgestellt durch das CVE Programm von einer CVE Numbering Authority (CNA) (Unstrukturiert).
HerstellerX.Org
≫
Produkt xorg-server
Default Statusunaffected
Version 0
Version < 21.1.24
Status affected
HerstellerX.Org
≫
Produkt xwayland
Default Statusunaffected
Version 0
Version < 24.1.13
Status affected
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.28% 0.203
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
meissner@suse.de 8.5 1.8 6
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE-122 Heap-based Buffer Overflow

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().

https://gitlab.freedesktop.org/xorg/xserver/-/commit/fbf7bac22e2c6bd627fb042742a23318263edae1
https://www.openwall.com/lists/oss-security/2026/07/08/2