filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker (tox-dev filelock)
At a glance
- Source
- NVD
- EPSS
- EPSS 0.21 % · percentile 12 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- GitHub_M
- NVD status
- Analyzed
Description
filelock is a platform-independent file lock for Python. From 3.32.6 until 4.2.1, SoftFileLock can follow a swapped symbolic link during the conditional os.access writability check for a node without its owner-write bit, allowing another local user on a platform and directory configuration that follows the link to infer whether a chosen path exists and is writable from the observable acquisition result. This issue is fixed in version 4.2.1.
Weaknesses (CWE)
- CWE-59 — Improper Link Resolution Before File Access
References
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | LOW 2.5 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N | GitHub_M |
| CVSS 3.1 | LOW 2.5 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N | NVD · security-advisories@github.com (Secondary) |
Advisories
- GHSA-9j6q-wvj5-jgjg — filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker
European references
- ENISA EUVD · EUVD-2026-105019
- GCVE · GCVE-0-2026-112912
Affected configurations (NVD CPE)
cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:*≥ 3.32.6 < 4.2.1
Affected products
| Product | Versions |
|---|---|
| tox-dev · filelock | affected >= 3.32.6, < 4.2.1 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |