CVE-2026-28786: Open WebUI vulnerable to path traversal in audio endpoint

# CVE-2026-28786: Open WebUI vulnerable to path traversal in audio endpoint

https://gcdradar.vercel.app/incidents/cve-2026-28786-open-webui-vulnerable-to-path-traversal-in-au · AIR-2026-0531 · closed 2026-03-27

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-03-27
- AI role: Attack on AI
- Products: Open WebUI
- CVE ids: CVE-2026-28786
- CVSS: 4.3

## Summary

An unsanitized filename field in Open WebUI's speech-to-text transcription endpoint permits information disclosure via a path traversal error message. Default deployments expose the absolute server data directory path in HTTP responses.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2026-03-27: CVE-2026-28786: Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. (https://nvd.nist.gov/vuln/detail/CVE-2026-28786)
- 2026-03-27: CVE-2026-28786: Open WebUI vulnerable to Path Traversal in `POST /api/v1/audio/transcriptions` (https://github.com/advisories/GHSA-vvxm-vxmr-624h)

## Sources

- 2026-03-27 GitHub Advisory Database: CVE-2026-28786: Open WebUI vulnerable to Path Traversal in `POST /api/v1/audio/transcriptions` https://github.com/advisories/GHSA-vvxm-vxmr-624h
- 2026-03-27 NVD: CVE-2026-28786: Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. https://nvd.nist.gov/vuln/detail/CVE-2026-28786

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.