Path Traversal in Wandb
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.
Vulnerability class: Path Traversal (Directory Traversal)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.012 (67.3th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/wandb/wandb/issues/12592 (issue-tracking)
- github.com/wandb/wandb/commit/e52558f3a6a94ea816af74969a13a35e5904cad6 (patch)
- github.com/wandb/wandb/releases/tag/v0.29.0 (release-notes)
- github.com/wandb/wandb/blob/v0.27.2/wandb/apis/public/files.py (technical-description)
- github.com/wandb/wandb (product)
- www.vulncheck.com/advisories/weights-biases-wandb-before-0.29.0-path-traversal-… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-91771?
- CVE-2026-91771 is a high-severity vulnerability in Wandb, classified under Path Traversal. CVSS score: 8.8/10. Published 2026-09-15.
- How severe is CVE-2026-91771?
- High severity. CVSS v3 base score is 8.8 out of 10.