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Vulnerability record · CVE-2025-26596 · published 25 February 2025

CVE-2025-26596: Tigervnc out-of-bounds write vulnerability

Tigervnc · Tigervnc

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.

7.8 CVSS 3.1 High EPSS 0.44% · top 63.8% CWE-787 · Out-of-bounds write
7.8CVSS 3.1 base score
0.44%EPSS exploitation probability, 30 days
NoNot in CISA KEV
4Affected product versions listed by NVD
18References
29 Jun 2026Last modified by NVD

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.

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

Affected products

4 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
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/errata/RHSA-2025:3976
https://access.redhat.com/errata/RHSA-2025:7163
https://access.redhat.com/errata/RHSA-2025:7165
https://access.redhat.com/errata/RHSA-2025:7458
https://access.redhat.com/security/cve/CVE-2025-26596 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2345256 Issue Tracking
https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html

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Source: NIST National Vulnerability Database (record CVE-2025-26596), CISA KEV, FIRST EPSS (scores of 2026-10-11). This page is refreshed as NVD updates the record.