ALT-PU-2026-10829-1 — xorg-xwayland

CVE-2026-55999

HIGH7.8

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.

Published: 2026-07-08Modified: 2026-07-09

CVSS 3.xHIGH 7.8

CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

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

CVE-2026-56000

CRITICAL9.0

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent() pointing into potentially reallocated memory.

Published: 2026-07-08Modified: 2026-07-09

CVSS 3.xHIGH 7.8

CVSS:3.x/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS 4.0CRITICAL 9.0

CVSS:4.0/CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

References

https://gitlab.freedesktop.org/xorg/xserver/-/commit/2779affbdb4354e894f490e56f962527d6125043
https://www.openwall.com/lists/oss-security/2026/07/08/2

Package update xorg-xwayland in branch sisyphus

Closed issues (2)

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.

Local attackers with a X connection able to provide GLX commit to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a Heap Use After Free, due to CommonMakeCurrent() pointing into potentially reallocated memory.