Description
filelock is a platform-independent file lock for Python. From 3.20.4 until 4.0.9, ReadWriteLock and AsyncReadWriteLock versions from 3.20.4 resolve the lock path and pass it to SQLite without rejecting a final symbolic link, allowing another local user who can create names in the lock directory to redirect database creation and locking or split mutual exclusion between targets. This issue is fixed in version 4.0.9.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| tox-dev | filelock | >= 3.20.4, < 4.0.9 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | python-filelock | 4.0.12-1 | — |
| Debian 13 | python-filelock | No fix yet | — |
| Debian 12 | python-filelock | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | python-filelock | No fix yet | — |
| Ubuntu 26.04 LTS | python-filelock | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 24.04 LTS | python-filelock | No fix yet | — |
| Ubuntu Pro 22.04 LTS | python-filelock | No fix yet | — |
| Ubuntu Pro 20.04 LTS | python-filelock | No fix yet | — |
| Ubuntu Pro 18.04 LTS | python-filelock | No fix yet | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
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federiconbaez/cortex9-filelock-sqlite-symlink-follow-model ★ 0 · Nov 9, 2026
Offline educational model of CVE-2026-112936 (filelock SQLite symlink follow)
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| PyPI | filelock | >= 3.20.4, < 4.0.9 | 4.0.9 | GHSA-j8f7-rjxc-mr56 |