CVE-2026-55999

high

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.

References

https://www.openwall.com/lists/oss-security/2026/07/08/2

https://gitlab.freedesktop.org/xorg/xserver/-/commit/fbf7bac22e2c6bd627fb042742a23318263edae1

Details

Source: Mitre, NVD

Published: 2026-07-08

Updated: 2026-07-09

Risk Information

CVSS v2

Base Score: 7.1

Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:C

Severity: High

CVSS v3

Base Score: 8.5

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

Severity: High

EPSS

EPSS: 0.00284