# CVE-2026-112913: filelock: ReadWriteLock on Windows acts on SQLite side files another local user places beside its database

Source: https://junglewise.ai/threats/cve-2026-112913-filelock-readwritelock-on-windows-acts-on-sqlite-side-files  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-05  
License: CC BY 4.0 with a link back

CVE-2026-112913 · Severity: low · CVSS 3.3 · Published 2026-11-05

filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock and AsyncReadWriteLock on Windows use _connect to attach SQLite to the lock database by pathname, allowing another local account that can create adjacent names to place a database-wal or database-journal side file before acquisition. An undeletable WAL file makes each read or write acquisition fail immediately with sqlite3.OperationalError regardless of timeout. Separately, when the database contains at least one table, a hot journal that grants the lock account modify rights can cause SQLite recovery to delete a file named by that journal only when the lock account has permission to delete the target. The issue requires a directory writable by another account, such as a shared Windows temporary directory, and does not affect private directories. This issue is fixed in version 4.2.1.

Technologies: [filelock (PyPI)](https://junglewise.ai/threats/technologies/filelock). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2026-112913 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-112913 being exploited in the wild.

**How severe is CVE-2026-112913?** Low severity, with a CVSS score of 3.3, published 5 November 2026.

**Which products and versions are affected?** filelock (PyPI) >= 3.20.4, <= 4.2.0, ECOSYSTEM:introduced=3.20.4,fixed=4.2.1.

**Is there a fix for CVE-2026-112913?** Yes. filelock (PyPI): upgrade to 4.2.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-112913?** Check whether you run filelock (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- filelock (PyPI): upgrade to 4.2.1 or later

  ```sh
  pip install "filelock>=4.2.1"
  ```


## Affected products

- filelock (PyPI) >= 3.20.4, <= 4.2.0, ECOSYSTEM:introduced=3.20.4,fixed=4.2.1

## Identifiers

- CVE-2026-112913
- GHSA-9vhv-jxww-xfm5

## Related threats

- [filelock StrictSoftFileLock symlink race privilege escalation](https://junglewise.ai/threats/cve-2026-112938-filelock-strictsoftfilelock-follows-a-symbolic-link-swapped-in)
- [filelock WindowsFileLock mode parameter permission enforcement failure](https://junglewise.ai/threats/cve-2026-112910-filelock-windowsfilelock-ignores-mode-a-0o600-lock-file-and-the)
- [filelock StrictSoftFileLock directory permission bypass](https://junglewise.ai/threats/cve-2026-112908-filelock-strictsoftfilelock-creates-its-claim-directories)
- [filelock: On Windows an oplock on a soft lock's marker holds SoftFileLock.acquire() past its timeout and blocks the stale break](https://junglewise.ai/threats/cve-2026-112907-filelock-on-windows-an-oplock-on-a-soft-lock-s-marker-holds)
- [filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftReadWriteLock and…](https://junglewise.ai/threats/cve-2026-112941-filelock-is-a-platform-independent-file-lock-for-python-from-4-1)