# filelock: ReadWriteLock follows a symlink at the lock path into SQLite

Advisory record · `GHSA-j8f7-rjxc-mr56`

- **Identifiers:** `GHSA-j8f7-rjxc-mr56` · `CVE-2026-112936`
- **State:** Confirmed
- **Severity:** CVSS 6.1 Medium
- **Critical:** No
- **Weakness (CWE):** [CWE-59](https://cwe.mitre.org/data/definitions/59.html) · [CWE-668](https://cwe.mitre.org/data/definitions/668.html)
- **Tags:** [Path traversal](https://agentprime.io/advisories/tag/path-traversal.md) · [Information disclosure](https://agentprime.io/advisories/tag/info-disclosure.md)
- **Published:** 28 Oct 2026
- **Updated:** 28 Oct 2026
- **Reviewed by a person:** No

Published by the GitHub Advisory Database at 28 Oct 2026, 21:08 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

## Affected packages

- `filelock` (PyPI): affected `>=3.20.4, <4.0.9`; fixed in `4.0.9`

## Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

## Severity and exploitation

- 6.1 Medium, CVSS 3.1: `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L`, from CNA (GitHub_M)

- **CISA KEV:** Not listed.
- **EPSS:** 0.0023, the 14th percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

## Timeline

- 31 Oct 2026, 14:07 UTC: First seen by agentprime
- 31 Oct 2026, 14:07 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-j8f7-rjxc-mr56)

## Sources

- [GitHub Advisory Database: GHSA-j8f7-rjxc-mr56](https://github.com/advisories/GHSA-j8f7-rjxc-mr56)
- [OSV: GHSA-j8f7-rjxc-mr56](https://osv.dev/vulnerability/GHSA-j8f7-rjxc-mr56)
- <https://github.com/tox-dev/filelock/security/advisories/GHSA-j8f7-rjxc-mr56>
- <https://nvd.nist.gov/vuln/detail/CVE-2026-112936>
- <https://github.com/tox-dev/filelock/commit/4d45e83caf7e31f9a12fb44526bdc07f70114f04>
- <https://github.com/tox-dev/filelock>
- <https://github.com/tox-dev/filelock/releases/tag/4.0.9>

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.

## Check whether this affects you

A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet.

- With the agentprime MCP server (<https://api.agentprime.io/mcp>), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: <https://agentprime.io/mcp.md>
- In a browser: <https://agentprime.io/check/> reads your lockfile in the browser, never uploading it.
- Whether it touches your code, with file and line: the Claude Code plugin, <https://agentprime.io/plugin.md>
- As JSON: <https://api.agentprime.io/v1/advisories/GHSA-j8f7-rjxc-mr56>, or `POST https://api.agentprime.io/v1/match` with your packages (<https://agentprime.io/api.md>)

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The web page: <https://agentprime.io/advisories/GHSA-j8f7-rjxc-mr56/>. Everything for agents: <https://agentprime.io/llms.txt>.