CVE-2026-112910

What it is

filelock is a platform-independent file lock for Python. From 3.10.0 until 4.2.1, filelock on Windows ignores the mode argument for WindowsFileLock files and the ReadWriteLock SQLite database. A lock created with mode=0o600 receives the parent directory's inheritable ACL because _open_non_reparse_fd and _nt_open do not create an owner-only security descriptor. Another local account with inherited access can read holder metadata or the lock database, modify those files where the ACL permits writes, or take the byte-range lock after release and delay later acquisitions. UnixFileLock is not affected, and mutual exclusion between cooperating processes continues to hold. This issue is fixed in version 4.2.1.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. Limited direct impact.

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-11-05 22:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-11-05 22:17 UTC Last updatedMost recent change to the record

Details

Published

2026-11-05 22:17 UTC

Last modified

2026-11-05 22:17 UTC

Weakness

CWE-732 · Incorrect permission assignment

Record status

Received

Attack profile CVSS 3.1 · 5.3

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

Low

Integrity

Low

Availability

Low