CVE-2026-112906Medium· 4.7▾ TwilightPoC availablefilelock 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 w…
▾ Twilight zone — High severity, or a signal on a lesser flaw
impact 25.9 · likelihood 0 · exploitation 12
A public proof-of-concept already exists for this vulnerability — see Exploit availability below.
Stakeholder-Specific Vulnerability Categorization from CISA's ADP record at CVE.org: whether exploitation is observed, whether an attack can be automated, and how much of the system is at stake. The CVSS score shown above comes from the assigning CNA record, not NVD.
Disclosure to exploitation, from the record and what we observed since indexing it.
Disclosed via CVEORG
Exploit / PoC code exists
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.
filelock >= 4.1.0, < 4.2.1Refer to the linked advisories for vendor-supplied fixes and affected version ranges.
Field changes observed since this record was first indexed.
Connected by shared product, vendor, weakness, or advisory.
CVE-2026-112914Medium· 5.3filelock: SoftFileLock stale-break restore follows a swapped-in symbolic link and hard-links a file of the user running the lock into the lock directory
CVE-2026-112935Medium· 4.7filelock: SoftFileLock stale-lock break removes a live lock file on a reused inode number and admits two holders
CVE-2026-112912Low· 2.5filelock: Symlink swap during SoftFileLock's writability check leaks whether a path exists and is writable by the lock taker
CVE-2026-112915Medium· 5.5filelock ReadWriteLock: a crafted lock database makes every acquire stall or hang regardless of timeout
CVE-2026-112939Medium· 4.7filelock: SoftFileLock removes a live holder's marker when another user forges the PID in a writable marker
CVE-2026-112909Medium· 6.1filelock: UnixFileLock truncates and chmods any regular file another user renames or hard-links onto the lock path