CVE-2026-112912
filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker
CVSS Score
2.5
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-59 |
| Vendor | tox-dev |
| Product | filelock |
| Published | Oct 20, 2026 |
| Last Updated | Oct 20, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
Low
Integrity
None
Availability
None
Affected Versions
tox-dev / filelock
>= 3.32.6, < 4.2.1
References
github.com: https://github.com/tox-dev/filelock/security/advisories/GHSA-9j6q-wvj5-jgjg github.com: https://github.com/tox-dev/filelock/pull/835 github.com: https://github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a github.com: https://github.com/tox-dev/filelock/releases/tag/4.2.1