CVE catalog

CVE-2026-112906

python-filelock affected and fixed versions

[CVE catalog]

filelock is a platform-independent file lock for Python. From 4.1.0 until 4.2.1, SoftFileLock versions from 4.1.0 can reuse a stale observation when an attacker pre-dates and removes its own marker, at least two lock-user processes are waiting, coarse or matching modification times preserve the observation, and an honest contender creates a fresh marker on the reused inode, causing that live marker to be removed as stale. This issue is fixed in version 4.2.1.

Severity
Medium · CVSS 4.7CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
Published
Source
[NVD] · [CVE record]
EPSS
0.21% · Oct 27, 2026

Projects and upstream resources

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Version impact has not been established. The original provider fields are retained below.

Provider details and historical evidence
Original provider fields
{
  "package_releases": [
    {
      "name": "python-filelock",
      "status": "vulnerable",
      "release": "sid",
      "version": "4.1.1-1"
    },
    {
      "name": "python-filelock",
      "status": "vulnerable",
      "release": "forky",
      "version": "4.1.1-1"
    },
    {
      "name": "python-filelock",
      "status": "vulnerable",
      "release": "trixie",
      "version": "3.18.0-1+deb13u1"
    },
    {
      "name": "python-filelock",
      "status": "vulnerable",
      "release": "bookworm",
      "version": "3.9.0-1+deb12u1"
    }
  ],
  "fixed_versions": [
    {
      "bug": 1151686,
      "name": "python-filelock",
      "type": "source",
      "origin": null,
      "release": "sid",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1151686,
      "name": "python-filelock",
      "type": "source",
      "origin": null,
      "release": "forky",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1151686,
      "name": "python-filelock",
      "type": "source",
      "origin": null,
      "release": "trixie",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1151686,
      "name": "python-filelock",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "not yet assigned",
      "fixed_version": ""
    }
  ],
  "distribution_packages": [
    {
      "name": "python-filelock",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            }
          ]
        }
      ],
      "release": "pro",
      "versions": [
        "3.12.2-1",
        "3.12.4-1",
        "3.13.1-1",
        "3.13.1-1ubuntu0.1~esm1"
      ],
      "ecosystem": "deb",
      "fixed_version": "",
      "provider_record_id": "UBUNTU-CVE-2026-112906"
    },
    {
      "name": "python-filelock",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            }
          ]
        }
      ],
      "release": "26.10",
      "versions": [
        "3.20.3-1",
        "3.29.4-1",
        "3.32.0-1",
        "3.32.2-1"
      ],
      "ecosystem": "deb",
      "fixed_version": "",
      "provider_record_id": "UBUNTU-CVE-2026-112906"
    },
    {
      "name": "python-filelock",
      "distro": "ubuntu",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            }
          ]
        }
      ],
      "release": "26.04",
      "versions": [
        "3.18.0-1",
        "3.20.0-1",
        "3.20.2-1",
        "3.20.3-1"
      ],
      "ecosystem": "deb",
      "fixed_version": "",
      "provider_record_id": "UBUNTU-CVE-2026-112906"
    },
    {
      "name": "filelock",
      "ranges": [
        {
          "fixed": "4.2.1",
          "introduced": "4.1.0",
          "last_affected": "",
          "start_excluding": ""
        }
      ],
      "ecosystem": "cpe",
      "fixed_version": "4.2.1",
      "provider_record_id": "NVD-CVE-2026-112906"
    }
  ]
}

[Debian bug #1151686]

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

  • [python3-filelock]Unknown

    Source package: [python-filelock]

    Details (2)

    • 3.9.0-1+deb12u1 · all · bookworm

      Affected

      dsa · python-filelock · debian · bookworm; dsa · python-filelock · debian · 12

    • 3.9.0-1+deb12u1 · all · bookworm

      Affected

      dsa · python-filelock · debian · bookworm; dsa · python-filelock · debian · 12

[Debian 13 (Trixie)]

  • [python3-filelock]Unknown

    Source package: [python-filelock]

    Details (2)

    • 3.18.0-1+deb13u1 · all · trixie

      Affected

      dsa · python-filelock · debian · 13

    • 3.18.0-1+deb13u1 · all · trixie

      Affected

      dsa · python-filelock · debian · 13

Observed:

References

[Debian Security Tracker] · [FIRST EPSS] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX]