CVE-2026-56000

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

Published Jul 8, 2026 CVSS 4.0 · 9 Critical EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6497-1 xorg-server security update
History
Type Values Removed Values Added
First Time appeared X.org
X.org xorg-server
X.org xwayland
Vendors & Products X.org
X.org xorg-server
X.org xwayland
Type Values Removed Values Added
Weaknesses CWE-825
References
Metrics threat_severity

None

cvssV3_1

{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title xorg-x11-server / xwayland GLX contextTags Use-After-Free in CommonMakeCurrent()
Weaknesses CWE-416
References
Metrics cvssV4_0

{'score': 9, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
suse
Published
Updated
Jul 8, 2026, 12:42 PM
Reserved
Jun 18, 2026, 9:26 AM
Status
Analyzed
Published
Jul 8, 2026, 9:16 AM
Modified
Jul 9, 2026, 7:47 PM
Severity
Important
Public date
Jul 8, 2026, 12:00 AM