It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2026-1415 advisory.

    filelock is a platform-independent file lock for Python. In versions prior to 3.20.1, a Time-of-Check-     Time-of-Use (TOCTOU) race condition allows local attackers to corrupt or truncate arbitrary user files     through symlink attacks. The vulnerability exists in both Unix and Windows lock file creation where     filelock checks if a file exists before opening it with O_TRUNC. An attacker can create a symlink pointing     to a victim file in the time gap between the check and open, causing os.open() to follow the symlink and     truncate the target file. All users of filelock on Unix, Linux, macOS, and Windows systems are impacted.
    The vulnerability cascades to dependent libraries. The attack requires local filesystem access and ability     to create symlinks (standard user permissions on Unix; Developer Mode on Windows 10+). Exploitation     succeeds within 1-3 attempts when lock file paths are predictable. The issue is fixed in version 3.20.1.
    If immediate upgrade is not possible, use SoftFileLock instead of UnixFileLock/WindowsFileLock (note:
    different locking semantics, may not be suitable for all use cases); ensure lock file directories have     restrictive permissions (chmod 0700) to prevent untrusted users from creating symlinks; and/or monitor     lock file directories for suspicious symlinks before running trusted applications. These workarounds     provide only partial mitigation. The race condition remains exploitable. Upgrading to version 3.20.1 is     strongly recommended. (CVE-2025-68146)

    filelock is a platform-independent file lock for Python. Prior to version 3.20.3, a TOCTOU race condition     vulnerability exists in the SoftFileLock implementation of the filelock package. An attacker with local     filesystem access and permission to create symlinks can exploit a race condition between the permission     validation and file creation to cause lock operations to fail or behave unexpectedly. The vulnerability     occurs in the _acquire() method between raise_on_not_writable_file() (permission check) and os.open()     (file creation). During this race window, an attacker can create a symlink at the lock file path,     potentially causing the lock to operate on an unintended target file or leading to denial of service. This     issue has been patched in version 3.20.3. (CVE-2026-22701)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Detections

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Amazon Linux 2023 : python3-filelock (ALAS2023-2026-1415)

medium Nessus Plugin ID 298128

Version 1.2

Version 1.1

Version 1.2 Apr 14, 2026, 9:52 AM CVSS metrics ("CVSSv2 score" set to 5.7) CVSS metrics ("CVSSv2 vector" set to "CVSS2#AV:L/AC:H/Au:S/C:P/I:C/A:C") CVSS metrics ("CVSSv3 score" set to 6.5) CVSS metrics ("CVSSv3 vector" set to "CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:H") CVSS temporal metrics ("CVSSv2 temporal vector" set to "CVSS2#E:POC/RL:OF/RC:C") CVSS temporal metrics ("CVSSv3 temporal vector" set to "CVSS:3.0/E:P/RL:O/RC:C") Exploit attributes ("Exploit available" set to "True") Exploit attributes ("Exploitability ease" changed from "No known exploits are available" to "Exploits are available") Plugin Feed: 202604140952
Version 1.1 Feb 6, 2026, 8:56 AM New Plugin Feed: 202602060856