CVE-2026-91771 json
Weights & Biases wandb before 0.29.0 Path Traversal via File Download
published 2026-09-15 55 d ago modified 2026-09-24 45 d ago also EUVD-2026-78247
- cvss
- 8.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 1.2%
- EPSS 1.2% chance of exploitation in 30 days, percentile 67%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- wandb wandb 0.29.0
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2026-91771 updated cvss 8.8
wandb: wandb: Arbitrary code execution via path traversal in file download
-
Red Hat Exploit Intelligence exploit-intelligence-tech-preview/vulnerability-analysis-rhel9 Red Hat AI Inference Server rhaiis/vllm-cpu-rhel9, rhaiis/vllm-tpu-rhel9affected: workaround, no fix planned “Will not fix”
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 51 d ago
Exploit prediction
1.17% chance of exploitation in the next 30 days, higher than 67% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N |
| CNA | 4.0 | 8.7 | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X |
Affected products
- wandb wandb
Classification
- Weakness
-
- CWE-22 Improper Limitation of a Pathname to a Restricted Directory
References
-
github.com
/wandb/wandb/commit/e52558f3a6a94ea816af74969a13a35e5904cad6
patch
-
github.com
/wandb/wandb/issues/12592
issue-tracking
-
github.com
/wandb/wandb/releases/tag/v0.29.0
release-notes
-
github.com
/wandb/wandb/blob/v0.27.2/wandb/apis/public/files.py#L319-L347
technical-description
-
github.com
/wandb/wandb
product
-
vulncheck.com
/advisories/weights-biases-wandb-before-0.29.0-path-traversal-via-file-download
third-party-advisory
Sources
- CVE List CVE-2026-91771
- NVD CVE-2026-91771
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.