---
id: CVE-2026-91771
title: >-
  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
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 s…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cwe:
  - CWE-22
vendor: wandb
product: wandb
affected:
  - wandb < 0.29.0
published: '2026-09-15'
updated: '2026-09-24'
sourceUpdated: '2026-09-24T21:08:22.573'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91771'
references:
  - url: 'https://github.com/wandb/wandb'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/wandb/wandb/blob/v0.27.2/wandb/apis/public/files.py#L319-L347
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/wandb/wandb/commit/e52558f3a6a94ea816af74969a13a35e5904cad6
    label: disclosure@vulncheck.com
  - url: 'https://github.com/wandb/wandb/issues/12592'
    label: disclosure@vulncheck.com
  - url: 'https://github.com/wandb/wandb/releases/tag/v0.29.0'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/weights-biases-wandb-before-0.29.0-path-traversal-via-file-download
    label: disclosure@vulncheck.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91771.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-91771'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2533555'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-91771'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91771'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.01167
epssPercentile: 0.65938
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-09-18T17:14:53.033262Z'
ingestedAt: '2026-09-15T02:19:07.441Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Important · affected: Exploit Intelligence, Red Hat AI Inference Server · no fix planned: Exploit Intelligence, Red Hat AI Inference Server · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-91771.json)