Executive brief
Windows NTFS, the file system used in modern Windows operating systems, contains a vulnerability where authorized users can follow symbolic links or junctions to access or modify files they should not have direct access to. An attacker with local access to a Windows system could exploit this to tamper with sensitive files, potentially compromising system integrity or escalating privileges.
Technical details
This vulnerability is a link-following (TOCTOU-style) flaw in Windows NTFS where improper validation before file access allows authorized local attackers to manipulate symbolic links or junctions. The attacker must have local file system access and appropriate permissions to exploit this. By creating or controlling symlinks, an attacker can redirect file operations to unintended locations, achieving local file tampering. The vulnerability requires local access and existing authorization, limiting the attack surface but enabling privilege escalation or data manipulation scenarios. A patch from Microsoft is expected to address the improper resolution logic.
Affected products
- Microsoft Windows NTFS <UNKNOWN>
Timeline
- 2026-09-08: disclosed