Cyber Posture

CVE-2025-26598

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 8.8th 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-2025-26598 is an out-of-bounds write vulnerability in X.Org Server and Xwayland. The flaw occurs in the GetBarrierDevice() function, which searches for a pointer device by its device ID and is intended to return NULL if no match is found. Instead, the function returns the last element of the list when no matching device ID exists, potentially leading to out-of-bounds memory access. The vulnerability is classified under CWE-787 (Out-of-bounds Write) with a CVSS v3.1 base score of 7.8.

A local attacker with low privileges can exploit this vulnerability with low complexity and no user interaction required. Successful exploitation grants high-impact access to confidentiality, integrity, and availability, enabling potential arbitrary code execution, data corruption, or system crashes through the out-of-bounds write.

Red Hat has issued multiple security errata addressing this issue, including RHSA-2025:2500, RHSA-2025:2502, RHSA-2025:2861, RHSA-2025:2862, and RHSA-2025:2865, which provide updated packages for affected Red Hat products incorporating fixes for the vulnerability.

Details

CWE(s)
CWE-787

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?

Out-of-bounds write and related memory corruption vulnerabilities (use-after-free, buffer/heap overflows) in Xwayland, as patched in TigerVNC server, enable remote exploitation over VNC connections for arbitrary code execution.

References