SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2025-26596

A heap overflow flaw was found in X.Org and Xwayland.

HIGH 7.8EPSS 0.44%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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
7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
0.44% probability · 38th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-787
Affected
tigervnc/tigervnc · x.org/x server · x.org/xwayland · redhat/enterprise linux
Source
secalert@redhat.com
EPSS trend
0%3%5%26 October 2026: 0.44%26 October 202626 October 2026

EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.