8.8High
CVE-2026-91771
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.
What this means for your business
- An attacker can use it remotely, over a network, without a login, but only after tricking someone into an action such as opening a file or a link.
- FIRST's prediction model gives it a 0.7% chance of attack attempts being seen in the next 30 days, ranking above 52% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
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Scoring
- CVSS
- 8.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H- CVSS v4
- 8.7
- Weakness
- CWE-22
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-15
- Last modified
- 2026-09-15
- Sources
- NVD
References
- https://github.com/wandb/wandb
- https://github.com/wandb/wandb/blob/v0.27.2/wandb/apis/public/files.py#L319-L347
- https://github.com/wandb/wandb/commit/e52558f3a6a94ea816af74969a13a35e5904cad6
- https://github.com/wandb/wandb/issues/12592
- https://github.com/wandb/wandb/releases/tag/v0.29.0
- https://www.vulncheck.com/advisories/weights-biases-wandb-before-0.29.0-path-traversal-via-file-download