# CVE-2026-45315

## Summary

- **CVE ID:** CVE-2026-45315
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N)
- **CWE:** CWE-79, CWE-434, CWE-646
- **Published:** May 15, 2026
- **Last Modified:** May 19, 2026

## Description

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.3, the audio transcription upload endpoint takes the file extension from the user-supplied filename and saves the file under CACHE_DIR/audio/transcriptions/.. The /cache/{path} route serves these files via FileResponse, which sets Content-Type from the on-disk extension and emits no Content-Disposition. A verified user with the default-on chat.stt permission can upload a polyglot WAV+HTML file named pwn.html and trick any other user into opening the resulting URL — the response comes back as text/html and any embedded <script> runs in the Open WebUI origin. This vulnerability is fixed in 0.9.3.

## Affected Products

- open-webui — open-webui (< 0.9.3)

## References

- [CNA](https://github.com/open-webui/open-webui/security/advisories/GHSA-m8f9-9whg-f4xr)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.19%
- **EPSS Percentile:** 8.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._