CVSS 3.1
5.3 mediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:LCVE-2026-112910
Medium (5.3) in tox-dev filelock. EPSS 0.2% estimated probability of exploitation activity in the next 30 days. Fixed in filelock 4.2.1.
On this page
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.
Severity
- EPSS
- 0.2% estimated probability of exploitation activity in the next 30 days; 5th percentile. Scored 2026-11-10. A forecast for this CVE across the internet, not for your own systems.
- CISA's assessment (SSVC)
- Exploitation: PoC · Automatable: no · Technical impact: partial, assessed 2026-11-09. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
- CWE
- CWE-732 Incorrect Permission Assignment for Critical Resource
- OWASP Top 10
- A01:2025 Broken Access Control
- Published
- Modified
- NVD analysis
- Awaiting analysis
- Record from
- the NVD, synced
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Explain CVE-2026-112910 for an engineer deciding whether to act. Use https://cve.bz/api/public/cves/CVE-2026-112910?via=ask-ai-copy and https://cve.bz/cve/CVE-2026-112910?via=ask-ai-copy as the source of truth: what is affected and which versions fix it, whether it is in CISA KEV, public exploits, and its EPSS (an internet-wide 30-day estimate of exploitation activity, not a forecast for my systems). If they give no fixed versions, use the CVE record https://cveawg.mitre.org/api/cve/CVE-2026-112910 or the vendor advisory, not third-party mirrors. Tell me how to check whether I am affected and how to verify a fix. Cite the sources and say where they are uncertain.Opens a third-party assistant; its answer is its own, not cve.bz's. The prompt holds only this CVE's id and public links.
Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| tox-dev filelock | >= 3.10.0, < 4.2.1 |
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-8mx5-7m5m-r77g | PyPI | filelock | >=3.10.0 <4.2.1 | 4.2.1 |
Linux distributions
| Distribution | Release | Package | Fixed in | Advisory |
|---|---|---|---|---|
| Ubuntu | 26.04:LTS, 26.10, Pro:18.04:LTS and 3 more | python-filelock | no fix listed | UBUNTU-CVE-2026-112910 |
| Azure Linux | 3 | python-filelock | no fix listed | AZL-112711 |
From the distributions' data via OSV.dev: Ubuntu Security Notices © Canonical Ltd., CC BY-SA 4.0; Microsoft's Azure Linux vulnerability data, MIT. Modified: reformatted and linked to CVE records. Credits. On the distributions' own pages: Ubuntu.
Attack patterns (CAPEC)
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits. More on the page of CWE-732 (11).
References
- https://github.com/tox-dev/filelock/commit/72786d41aa25159ad28c1bcf4291738b135b2c6c
- https://github.com/tox-dev/filelock/commit/e1e825b1992f69fb6b346dc395d5ae4893536c0a
- https://github.com/tox-dev/filelock/pull/835
- https://github.com/tox-dev/filelock/releases/tag/4.2.1
- https://github.com/tox-dev/filelock/security/advisories/GHSA-8mx5-7m5m-r77g