CVE-2026-56000 PUBLISHED

xorg-x11-server / xwayland GLX contextTags Use-After-Free in CommonMakeCurrent()

Assigner: suse
Reserved: 18.06.2026 Published: 08.07.2026 Updated: 08.07.2026

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.

Metrics

CVSS 4.0

CVSS Vector: 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
CVSS Score: 9

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	High	Confidentiality	High
Attack Complexity	High	Integrity	High	Integrity	High
Attack Requirements	None	Availability	High	Availability	High
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	X.Org
Product	xorg-x11-server
Versions	Default: unaffected affected from 0 to 21.1.24 (excl.)

Vendor	X.Org
Product	xwayland
Versions	Default: unaffected affected from 0 to 24.1.13 (excl.)

Credits

Anonymous working with Trend Micro Zero Day Initiative. finder

References

Problem Types

CWE-416 Use after free CWE

Impacts

CAPEC-234 Hijacking a privileged process