CVE-2026-112913tox-dev filelock time-of-check to time-of-use race
CVE-2026-112913 is a time-of-check to time-of-use race in tox-dev filelock, rated low (3.3 on CVSS 3.1).
Why this priority: Low severity, with no exploitation signal.
Published · Updated · NVD status: Awaiting Analysis
What it is
Something is checked, then changed by an attacker before it is used.
How it is reached
An attacker can exploit it by someone who can already run code or sign in on the machine, with an ordinary user account, and nobody has to click anything.
What an attacker gains
The direct impact is limited: partial access to data or a partial outage. In practice, this kind of flaw lets an attacker win a timing window to bypass a check or corrupt shared state.
Is it being exploited?
CISA's SSVC assessment notes a public proof of concept.
What to do
- Upgrade tox-dev filelock to 4.2.1 or later.
- Limit who can run code or sign in on the hosts that run it.
Description from NVD
filelock is a platform-independent file lock for Python. From 3.20.4 until 4.2.1, ReadWriteLock and AsyncReadWriteLock on Windows use _connect to attach SQLite to the lock database by pathname, allowing another local account that can create adjacent names to place a database-wal or database-journal side file before acquisition. An undeletable WAL file makes each read or write acquisition fail immediately with sqlite3.OperationalError regardless of timeout. Separately, when the database contains at least one table, a hot journal that grants the lock account modify rights can cause SQLite recovery to delete a file named by that journal only when the lock account has permission to delete the target. The issue requires a directory writable by another account, such as a shared Windows temporary directory, and does not affect private directories. This issue is fixed in version 4.2.1.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Request handlers and jobs that share state. The flaw sits between concurrent requests or processes.
Trust boundaries in play
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- Between concurrent requests or processes. An attacker who crosses it can win a timing window to bypass a check or corrupt shared state.
Questions to answer about your own systems
- Where does tox-dev filelock run in your systems, and at which version?
- Which of those hosts also run code or users you do not fully trust?
- What can it reach once compromised: which data stores, secrets and services?
Read more
Patches and commits
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.