CVE-2026-91771 Weights & Biases wandb before 0.29.0 Path Traversal via File Download
Attackers controlling the backend can exploit path traversal in wandb to write files outside the download directory, potentially enabling code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-91771?
CVE-2026-91771 is a high-severity path traversal vulnerability in wandb, published on 15 Sep 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Weights & Biases wandb before 0.29.0 fails to validate the file name from server responses in the File.download function, allowing path traversal attacks. Attackers controlling the backend can supply file names with directory traversal sequences to write files outside the intended download directory, potentially enabling code execution through modification of shell startup files or Python import paths.
Weakness: CWE-22
Which versions are affected by CVE-2026-91771?
How do I fix CVE-2026-91771?
No fix has been published for CVE-2026-91771 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-91771 being exploited?
There is no known exploitation of CVE-2026-91771 in the wild and no public exploit code.
Sources
Also known as GHSA-h5x7-chgg-fqcc.