{"id":"CVE-2026-112915","kind":"vulnerability","aliases":["CVE-2026-112915"],"related":[],"title":"filelock: crafted SQLite lock database can hang Python lock acquisition","description":"filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock can open a crafted SQLite lock database without bounding schema and query work, allowing another local user who can replace the database to make acquisition stall or hang; versions from 3.20.4 expose this on initial per-instance opening, and versions from 3.30.0 repeat the exposure on every acquisition. This issue is fixed in version 4.2.1.","summary":"filelock's ReadWriteLock opens a SQLite lock database without limiting schema and query work, so a crafted database can make lock acquisition stall or hang. An attacker who is a local user able to replace that database causes a denial of service, not code execution.","severity":"medium","cvss":5.5,"epss":null,"exploited":false,"exploited_at":null,"products":[{"name":"tox-dev filelock","fixed":["4.2.1"],"affected":">= 3.20.4, < 4.2.1","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["filelock","package","python","self-hosted"],"not_affected_if":["no-readwritelock-usage","private-lock-path","single-user-host"],"how_to_check":"- Run `pip show filelock` or `python -c \"import filelock; print(filelock.__version__)\"` and check whether the version is at least `3.20.4` and below `4.2.1`\n- Check whether the application uses `ReadWriteLock` from filelock, since the flaw is in that class","fix":"- Upgrade filelock to `4.2.1` or later with `pip install -U \"filelock>=4.2.1\"`","status":"open","published_at":"2026-10-20T15:17:15+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","triaged_at":"2026-10-25T04:12:32+00:00","updated_at":"2026-10-25T04:12:32+00:00","category":"package","confidence":0.7,"triage":{"at":"2026-10-25T04:12:32Z","model":"claude-haiku-5-5","output":{"fix":"- Upgrade filelock to `4.2.1` or later with `pip install -U \"filelock>=4.2.1\"`","reach":"local","title":"filelock: crafted SQLite lock database can hang Python lock acquisition","impact":"low","summary":"filelock's ReadWriteLock opens a SQLite lock database without limiting schema and query work, so a crafted database can make lock acquisition stall or hang. An attacker who is a local user able to replace that database causes a denial of service, not code execution.","category":"package","nicknames":[],"who_cares":["python","filelock","self-hosted"],"confidence":0.7,"needs_auth":"yes","worst_case":"Lock acquisition hangs, stalling the application (denial of service)","analyst_note":"","how_to_check":"- Run `pip show filelock` or `python -c \"import filelock; print(filelock.__version__)\"` and check whether the version is at least `3.20.4` and below `4.2.1`\n- Check whether the application uses `ReadWriteLock` from filelock, since the flaw is in that class","needs_analyst":false,"not_affected_if":["no-readwritelock-usage","single-user-host","private-lock-path"],"who_is_affected":"Python applications that use filelock's ReadWriteLock on a lock database path that another local user can write to, such as a shared directory on a multi-user host. Single-user machines and containers where only the application user can write the lock path are much less exposed. Projects that do not use ReadWriteLock are not affected by this flaw.","user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"medium"},"cost_usd":0.000617,"input_tokens":3396,"output_tokens":555,"severity_before":"medium"},"analyst_status":null,"analyst_note":null,"search":"'-112915':13A,16A '-2026':12A,15A '3.20.4':83C,117C '3.30.0':129C '4.2.1':85C,142C 'abl':59B 'acquisit':10A,48B,111C,135C 'allow':100C 'anoth':101C 'attack':53B 'bound':95C 'caus':64B 'code':70B 'craft':2A,43B,90C 'cve':11A,14A 'databas':5A,34B,44B,63B,93C,108C 'denial':66B 'dev':19A 'everi':134C 'execut':71B 'expos':118C 'exposur':132C 'file':78C 'filelock':1A,20A,21B,27B,72C 'fix':139C 'hang':7A,51B,114C 'host':26B 'independ':77C 'initi':121C 'instanc':124C 'issu':137C 'limit':36B 'local':57B,102C 'lock':4A,9A,33B,47B,79C,92C 'make':46B,110C 'open':30B,88C,125C 'packag':22B 'per':123C 'per-inst':122C 'platform':76C 'platform-independ':75C 'python':8A,23B,81C 'queri':39B,98C 'readwritelock':29B,86C 'repeat':130C 'replac':61B,106C 'schema':37B,96C 'self':25B 'self-host':24B 'servic':68B 'sqlite':3A,32B,91C 'stall':49B,112C 'tox':18A 'tox-dev':17A 'user':58B,103C 'version':115C,127C,141C 'without':35B,94C 'work':40B,99C","nicknames":[],"mitigations":[],"who_affected":"Python applications that use filelock's ReadWriteLock on a lock database path that another local user can write to, such as a shared directory on a multi-user host. Single-user machines and containers where only the application user can write the lock path are much less exposed. Projects that do not use ReadWriteLock are not affected by this flaw.","tier":"C","verified":{},"analyst_revisit_at":null,"first_public_at":"2026-10-20T15:17:15+00:00","kev":null,"cvss_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvss_by":"security-advisories@github.com","poc_count":0,"sources":[{"source":"nvd","external_id":"CVE-2026-112915","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-112915","severity":null,"published_at":"2026-10-20T15:17:15+00:00","modified_at":"2026-10-21T21:15:34+00:00","first_seen_at":"2026-10-23T21:57:20+00:00","fetched_at":"2026-10-23T22:28:58+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}