CVE-2026-2636

MEDIUM

5.5

Description

This vulnerability is caused by a CWE‑159: "Improper Handling of Invalid Use of Special Elements" weakness, which leads to an unrecoverable inconsistency in the CLFS.sys driver. This condition forces a call to the KeBugCheckEx function, allowing an unprivileged user to trigger a system crash. Microsoft silently fixed this vulnerability in the September 2025 cumulative update for Windows 11 2024 LTSC and Windows Server 2025. Windows 25H2 (released in September) was released with the patch. Windows 1123h2 and earlier versions remain vulnerable.

CVE Details

CVSS v3.1 Score5.5

SeverityMEDIUM

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

Attack VectorLOCAL

ComplexityLOW

Privileges RequiredLOW

User InteractionNONE

Published2/25/2026

Last Modified2/27/2026

Sourcenvd

Honeypot Sightings0

Weaknesses (CWE)

CWE-159

References

https://www.fortra.com/security/advisories/research/fr-2026-001(df4dee71-de3a-4139-9588-11b62fe6c0ff)

IOC Correlations

No correlations recorded

This product uses data from the NVD API but is not endorsed or certified by the NVD.