Cyber Posture

CVE-2025-26600

High

Published: 25 February 2025

Published
25 February 2025
Modified
06 April 2026
KEV Added
Patch
CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0003 8.1th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Description

Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.

Security Summary

CVE-2025-26600 is a use-after-free vulnerability (CWE-416) affecting X.Org and Xwayland. The flaw arises when a device is removed while still in a frozen state, causing events queued for that device to persist even after the device structure is freed. Subsequent replay of these events triggers the use-after-free condition. The vulnerability carries a CVSS v3.1 base score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H).

A local attacker with low privileges can exploit this vulnerability due to its low attack complexity and lack of required user interaction. Successful exploitation grants high-impact access to confidentiality, integrity, and availability, potentially allowing arbitrary code execution or system compromise within the affected X server context.

Red Hat has issued multiple errata addressing this issue, including RHSA-2025:2500, RHSA-2025:2502, RHSA-2025:2861, RHSA-2025:2862, and RHSA-2025:2865, which provide patched packages for vulnerable X.Org and Xwayland components on supported systems.

Details

CWE(s)
CWE-416

Affected Products

tigervnc
tigervnc
all versions
x.org
x server
≤ 21.1.16
x.org
xwayland
≤ 24.1.6
redhat
enterprise linux
7.0, 8.0, 9.0

MITRE ATT&CK Enterprise Techniques

T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
Why these techniques?

Use-after-free and related memory corruption vulnerabilities (e.g., buffer overflows, OOB writes) in Xwayland, addressed in TigerVNC updates, occur during input/event processing (e.g., PlayReleasedEvents, Xkb functions), enabling remote code execution via crafted events from a malicious VNC client.

References