CVE-2025-26596

HIGH

Tigervnc < 21.1.16 - Out-of-Bounds Write

Title source: rule

Description

A heap overflow flaw was found in X.Org and Xwayland. The computation of the length in XkbSizeKeySyms() differs from what is written in XkbWriteKeySyms(), which may lead to a heap-based buffer overflow.

References (17)

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2500

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2502

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2861

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2862

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2865

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2866

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2873

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2874

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2875

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2879

[Third Party Advisory] https://access.redhat.com/errata/RHSA-2025:2880

[Third Party Advisory] https://access.redhat.com/security/cve/CVE-2025-26596

[Issue Tracking] https://bugzilla.redhat.com/show_bug.cgi?id=2345256

[Mailing List] https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html

[Vendor Advisory] https://access.redhat.com/errata/RHSA-2025:7163

[Vendor Advisory] https://access.redhat.com/errata/RHSA-2025:7165

[Vendor Advisory] https://access.redhat.com/errata/RHSA-2025:7458

Scores

CVSS v3 7.8

EPSS 0.0006

EPSS Percentile 18.0%

Attack Vector LOCAL

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

Classification

CWE

CWE-787

Status published

Affected Products (6)

x.org/x_server < 21.1.16

tigervnc/tigervnc

x.org/xwayland < 24.1.6

redhat/enterprise_linux

Timeline

Published Feb 25, 2025

Tracked Since Feb 18, 2026