Windows
CVE-2026-2636
MEDIUM
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
Lifecycle Timeline
2DescriptionCVE.org
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.
AnalysisAI
Local denial of service in Windows CLFS.sys driver allows unprivileged users to crash the system through improper handling of special elements. Affected versions include Windows 11 2024 LTSC and Windows Server 2025 prior to the September 2025 cumulative update, while Windows 25H2 and later contain the patch. No public exploit code is currently available, and the vulnerability carries a CVSS score of 5.5 with zero estimated probability of exploitation.
Technical ContextAI
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. Window
Affected ProductsAI
This vulnerability is caused by a CWE‑159: "Improper Handling of Invalid Use of Special Elements" weakness, which leads to an unrecoverable inconsiste
RemediationAI
Monitor vendor advisories for a patch.
Windows Win32k fails to properly handle objects in memory, allowing local privilege escalation exploited in the wild in
A privilege escalation vulnerability (CVSS 5.5). Risk factors: actively exploited (KEV-listed), EPSS 94% exploitation pr
Windows Internet Shortcut Files (.url) contain an external control vulnerability (CVE-2025-33053, CVSS 8.8) that enables
Windows SMB contains an improper access control vulnerability (CVE-2025-33073, CVSS 8.8) enabling authenticated attacker
Twonky Server 8.5.2 on Linux and Windows allows unauthenticated access to the admin log file through a web service API b
An unrestricted file upload vulnerability exists in MiniWeb HTTP Server <= Build 300 that allows unauthenticated remote
FreeFloat FTP Server contains multiple critical design flaws that allow unauthenticated remote attackers to upload arbit
Serviio Media Server versions 1.4 through 1.8 on Windows contain an unauthenticated command injection in the /rest/actio
Twonky Server 8.5.2 uses hard-coded cryptographic keys for encrypting the administrator password. Combined with the cred
Mako Server versions 2.5 and 2.6 contain an unauthenticated OS command injection via the tutorial interface at examples/
React Native Metro Development Server binds to external interfaces by default and contains an OS command injection endpo
External control of file name or path in Windows NTLM allows an unauthorized attacker to perform spoofing over a network
Same technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today