filelock is a platform-independent file lock for Python. From 3.10.0 until 4.2.1, filelock on Windows ignores the mode argument for WindowsFileLock files and the ReadWriteLock SQLite database. A lock created with mode=0o600 receives the parent directory's inheritable ACL because _open_non_reparse_fd and _nt_open do not create an owner-only security descriptor. Another local account with inherited access can read holder metadata or the lock database, modify those files where the ACL permits writes, or take the byte-range lock after release and delay later acquisitions. UnixFileLock is not affected, and mutual exclusion between cooperating processes continues to hold. This issue is fixed in version 4.2.1.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-8mx5-7m5m-r77g | filelock: WindowsFileLock ignores mode: a 0o600 lock file and the ReadWriteLock database inherit the directory ACL |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 06 Nov 2026 12:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-279 | |
| References |
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| Metrics |
threat_severity
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threat_severity
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Fri, 06 Nov 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
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| First Time appeared |
Tox-dev
Tox-dev filelock |
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| Vendors & Products |
Tox-dev
Tox-dev filelock |
Thu, 05 Nov 2026 22:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | filelock is a platform-independent file lock for Python. From 3.10.0 until 4.2.1, filelock on Windows ignores the mode argument for WindowsFileLock files and the ReadWriteLock SQLite database. A lock created with mode=0o600 receives the parent directory's inheritable ACL because _open_non_reparse_fd and _nt_open do not create an owner-only security descriptor. Another local account with inherited access can read holder metadata or the lock database, modify those files where the ACL permits writes, or take the byte-range lock after release and delay later acquisitions. UnixFileLock is not affected, and mutual exclusion between cooperating processes continues to hold. This issue is fixed in version 4.2.1. | |
| Title | filelock: WindowsFileLock ignores mode: a 0o600 lock file and the ReadWriteLock database inherit the directory ACL | |
| Weaknesses | CWE-732 | |
| References |
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| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-11-05T21:47:35.134Z
Reserved: 2026-10-19T20:16:09.857Z
Link: CVE-2026-112910
No data.
Status : Awaiting Analysis
Published: 2026-11-05T22:17:46.877
Modified: 2026-11-06T21:40:43.450
Link: CVE-2026-112910
OpenCVE Enrichment
Updated: 2026-11-06T14:00:07Z
Github GHSA