🛡️ CVE-2026-56000 on Ubuntu — xorg-server

⚪ Unknown ✅ No Known Exploit OSV

N/A

CVSS Score

0 Low4 Medium7 High9 Critical10

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.

Distribution advisory

This page covers CVE-2026-56000 as tracked by Ubuntu, for the package xorg-server. No fixed version has been recorded for this distribution yet.

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

Weakness class

UBUNTU-CVE-2026-56000 is classified as CWE-416: Use After Free. Memory is used after being released, so its contents may already belong to something else.

Affected software

UBUNTU-CVE-2026-56000 is recorded against 4 packages.

xorg-server
xorg-server-hwe-16.04
xorg-server-hwe-18.04
xwayland

Timeline and source

Published on 8 July 2026 and last revised on 15 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

ubuntu.com (Report)
www.cve.org (Report)
www.openwall.com (Report)

Details

Severity Unknown

CVSS Score N/A

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

CWE N/A

Public Exploit ✅ No

Source OSV

Published 2026-07-08

Updated 2026-08-11

Modified 2026-07-15

Fix URL N/A

Affected Packages

Software	From version	Fixed in
xorg-server	—	—
xorg-server-hwe-16.04	—	—
xorg-server-hwe-18.04	—	—
xwayland	—	—

References

REPORT https://ubuntu.com/security/CVE-2026-56000

REPORT https://www.cve.org/CVERecord?id=CVE-2026-56000

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

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