CVE-2026-112935
Full vulnerability record from the local CVENow database.
Description
filelock is a platform-independent file lock for Python. From 3.22.0 until 4.2.1, SoftFileLock can break a stale marker after an attacker frees its own marker following the stale read, an honest contender creates a live successor on the reused inode, and the successor's modification time is not newer than the saved observation, causing the live marker to be removed and two holders to be admitted. This issue is fixed in version 4.2.1.
Severity
MEDIUM
CVSS score
4.7
(v3.1)
Vulnerability status
Modified
Source identifier
Published
2026-10-20 15:17:16.243000
Last modified
2026-10-28 15:17:02.940000
View original CVE JSON
{
"id": "CVE-2026-112935",
"sourceIdentifier": "[email protected]",
"published": "2026-10-20T15:17:16.243",
"lastModified": "2026-10-28T15:17:02.940",
"vulnStatus": "Modified",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "filelock is a platform-independent file lock for Python. From 3.22.0 until 4.2.1, SoftFileLock can break a stale marker after an attacker frees its own marker following the stale read, an honest contender creates a live successor on the reused inode, and the successor's modification time is not newer than the saved observation, causing the live marker to be removed and two holders to be admitted. This issue is fixed in version 4.2.1."
}
],
"affected": [
{
"source": "[email protected]",
"affectedData": [
{
"vendor": "tox-dev",
"product": "filelock",
"versions": [
{
"version": ">= 3.22.0, < 4.2.1",
"status": "affected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "[email protected]",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
"baseScore": 4.7,
"baseSeverity": "MEDIUM",
"attackVector": "LOCAL",
"attackComplexity": "HIGH",
"privilegesRequired": "LOW",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "HIGH",
"availabilityImpact": "NONE"
},
"exploitabilityScore": 1.0,
"impactScore": 3.6
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-28T14:16:43.594543Z",
"id": "CVE-2026-112935",
"options": [
{
"exploitation": "poc"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
{
"source": "[email protected]",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-367"
}
]
}
],
"configurations": [
{
"nodes": [
{
"operator": "OR",
"negate": false,
"cpeMatch": [
{
"vulnerable": true,
"criteria": "cpe:2.3:a:tox-dev:filelock:*:*:*:*:*:python:*:*",
"versionStartIncluding": "3.22.0",
"versionEndExcluding": "4.2.1",
"matchCriteriaId": "5011FF77-7621-4E3E-8642-79A413FEAE97"
}
]
}
]
}
],
"references": [
{
"url": "https://github.com/tox-dev/filelock/commit/740ff666b62a88496c8d7394e4e6230605e4d62b",
"source": "[email protected]",
"tags": [
"Patch"
]
},
{
"url": "https://github.com/tox-dev/filelock/pull/843",
"source": "[email protected]",
"tags": [
"Patch"
]
},
{
"url": "https://github.com/tox-dev/filelock/releases/tag/4.2.1",
"source": "[email protected]",
"tags": [
"Release Notes"
]
},
{
"url": "https://github.com/tox-dev/filelock/security/advisories/GHSA-fq56-3cx3-fjxp",
"source": "[email protected]",
"tags": [
"Exploit",
"Mitigation",
"Patch",
"Vendor Advisory"
]
},
{
"url": "https://github.com/tox-dev/filelock/security/advisories/GHSA-fq56-3cx3-fjxp",
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"tags": [
"Exploit",
"Mitigation",
"Patch",
"Vendor Advisory"
]
}
]
}