{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "3.22.0"
                  },
                  {
                    "fixed": "4.2.1"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StringRangeExpression"
              },
              {
                "range": [
                  {
                    "fixed": "eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc"
                  }
                ],
                "source": "REFERENCES_COMMIT"
              },
              {
                "original_tag": "4.2.1",
                "range": [
                  {
                    "fixed": "60331bb89f325020b48bc51bde904c6446384e4a"
                  }
                ],
                "source": "REFERENCES_TAG"
              }
            ]
          },
          "events": [
            {
              "introduced": "1dd2465cef7e5c189feaa16698a3ec3f33a653b0"
            },
            {
              "fixed": "60331bb89f325020b48bc51bde904c6446384e4a"
            },
            {
              "fixed": "eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc"
            }
          ],
          "repo": "https://github.com/tox-dev/filelock",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-rfpc-qcw5-3pc4"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-345"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112939.json"
  },
  "details": "filelock is a platform-independent file lock for Python. From 3.22.0 until 4.2.1, SoftFileLock can trust a forged process identifier in a marker that an attacker can modify but cannot remove, allowing an authorized contender such as another process of the holder's account or root to act as a confused deputy, remove the live marker, and admit another holder. This issue is fixed in version 4.2.1.",
  "id": "CVE-2026-112939",
  "modified": "2026-10-22T02:30:55.575877250Z",
  "published": "2026-10-20T14:38:52.373Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/112xxx/CVE-2026-112939.json"
    },
    {
      "type": "FIX",
      "url": "https://github.com/tox-dev/filelock/commit/eeceaa846cbe4df72718d94c8371ca1ab8f5b3cc"
    },
    {
      "type": "FIX",
      "url": "https://github.com/tox-dev/filelock/pull/836"
    },
    {
      "type": "WEB",
      "url": "https://github.com/tox-dev/filelock/releases/tag/4.2.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/tox-dev/filelock/security/advisories/GHSA-rfpc-qcw5-3pc4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-112939"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "filelock: SoftFileLock removes a live holder's marker when another user forges the PID in a writable marker"
}