TI-2026-81961 Aliases CVE-2026-93515 GHSA-q227-m872-459m

Use-after-free in X.Org X Server Present extension

LOW 29CWE-416Published 2026-10-28 · Updated 2026-11-06

Key facts

Attack vector: Local
Privileges required: Low
User interaction: None
Attack complexity: Low
Attack requirements: None
Impact type: Denial of service
Confidentiality · integrity · availability: None · None · High
Fix status: Partial Red Hat: 5 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

X.org xorg-x11-server before 21.1.25 and x.org xwayland before 24.1.14 contain a use-after-free in present_clear_window_notifies() (CWE-416). A local client with low privileges can use it to crash the X server or potentially execute code in its context.

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Description from the CNA

A use-after-free in present_clear_window_notifies() in the X.org X Server before 21.1.25 and X Wayland before 24.1.14 could be used by malicious X clients to crash or potentially execute code in the X server context.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV

EPSS 0.00194 9th percentileScored 2026-11-07

Fix Partial xorg-x11-server (X.org): 21.1.25xwayland (x.org): 24.1.14Red Hat: 5 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation: None
Automatable: No
Technical impact: Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

Vendor	Product	Affected versions	Fixed in	Status	Source
x.org	xorg-x11-server	before 21.1.25	21.1.25	Patch available	CNA
x.org	xwayland	before 24.1.14	24.1.14	Patch available	CNA

xorg-x11-server Vendorx.org Affected before 21.1.25 Fixed in 21.1.25 Patch available CNA
xwayland Vendorx.org Affected before 24.1.14 Fixed in 24.1.14 Patch available CNA

Remediation

Upgrade xorg-x11-server to 21.1.25 and xwayland to 24.1.14. The sources list no fixed version for Red Hat Enterprise Linux 6 (no fix planned) and for Red Hat Enterprise Linux 7, 8, 9 and 10 (none available).

Written with Claude Haiku 5.5 from the sources below · 2026-10-29

Fix · CNA xorg-x11-server (X.org) Fixed in 21.1.25
Fix · CNA xwayland (x.org) Fixed in 24.1.14

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

Release · 2026-10-28
x.org xorg-x11-server 21.1.25
10 records Highest priority Priority LOW 10 LOW
Other records, highest priority first
- TI-2026-82016 Heap buffer overflow in X.Org X Server XInput2 request handlingPriority LOW 35
- TI-2026-82013 X.Org Server Glamor CopyArea Heap Buffer OverflowPriority LOW 35
- TI-2026-82007 Heap buffer overflow in X.Org X server XKB keycode range handlingPriority LOW 35
Show all 10 records →
Release · 2026-10-28
x.org xwayland 24.1.14
10 records Highest priority Priority LOW 10 LOW
Other records, highest priority first
- TI-2026-81987 Heap buffer overflow in X.Org Server GLX RenderLarge requestPriority LOW 38
- TI-2026-82016 Heap buffer overflow in X.Org X Server XInput2 request handlingPriority LOW 35
- TI-2026-82013 X.Org Server Glamor CopyArea Heap Buffer OverflowPriority LOW 35
Show all 10 records →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

Product	Status	Plan or fix
Red Hat Enterprise Linux 10	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 6	Affected	No fix planned: Out of support scope
Red Hat Enterprise Linux 7	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 8	Affected	No fix yet: Fix deferred
Red Hat Enterprise Linux 9	Affected	No fix yet: Fix deferred

Timeline

2026-10-28 Threatist record created from CVE-2026-93515
2026-10-28 Alias added: GHSA-q227-m872-459m
2026-10-30 Priority changed: MEDIUM → LOW
2026-11-06 CISA SSVC decision points changed

References

Patch 1

https://gitlab.freedesktop.org/xorg/xserver/-/commit/1b6955c3108e6b43433aefe860070708e6f43d1b

TI-2022-25238 In X.Org X server 20.11 through 21.1.16, when a client application uses easystroke for… CVSS 3.1HIGH 7.7
TI-1999-00519 An X server's access control is disabled (e.g. CVSS 2.0HIGH 10.0
TI-2021-11657 LookupCol.c in X.Org X through X11R7.7 and libX11 before 1.7.1 might allow remote… CVSS 3.1CRITICAL 9.8
TI-2018-10465 An issue was discovered in libX11 through 1.6.5. CVSS 3.0CRITICAL 9.8
TI-2004-00826 Multiple vulnerabilities in libXpm for 6.8.1 and earlier, as used in XFree86 and other… CVSS 2.0HIGH 10.0
TI-2016-08240 Multiple integer overflows in libXpm before 3.5.12, when a program requests parsing XPM… CVSS 3.0CRITICAL 9.8

See all 206 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences