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.
Affected products
tox-dev: filelock
References5
- github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-… ExploitMitigationPatchVendor Advisory
- github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-… ExploitMitigationPatchVendor Advisory
- github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5… Patch
- github.com/tox-dev/filelock/pull/835 Patch
- github.com/tox-dev/filelock/releases/tag/4.2.1 Release Notes
Metrics
- CVSS 3.1
-
2.5
LOW
Score source: CNA
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N - EPSS — exploit probability
- 0% percentile: 12 · as of 9 November 2026
- CWE
- CWE-59
Could this be exploited in your environment?
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