PT-2026-40212 · Microsoft · Common Log File System Driver+1

Published 2026-05-12 · Updated 2026-05-12 · CVE-2026-40397

Positive Technologies (AI Summary)

CVSS v3.1

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Windows Common Log File System Driver (affected versions not specified)

Description An integer underflow (wrap or wraparound) in the Windows Common Log File System Driver allows an authorized attacker to elevate privileges locally to SYSTEM level.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

DoS

Integer Underflow

Weakness Enumeration

CWE-191

Related Identifiers

BDU:2026-07124

CVE-2026-40397

Affected Products

Common Log File System Driver

Windows

References · 6

• https://bdu.fstec.ru/vul/2026-07124 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-40397 · Vendor Advisory
• https://msrc.microsoft.com/update-guide/en-US/advisory/CVE-2026-40397 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-40397 · Security Note
• http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2026-40397 · Security Note
• https://twitter.com/windowsforum/status/2054318337354522724 · Twitter Post