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.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-m8f9-9whg-f4xr | Open WebUI has stored XSS via attacker-controlled file extension in /api/v1/audio/transcriptions |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 15 May 2026 23:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Open-webui
Open-webui open-webui |
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| Vendors & Products |
Open-webui
Open-webui open-webui |
Fri, 15 May 2026 22:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | Open WebUI: Stored XSS via attacker-controlled file extension in /api/v1/audio/transcriptions | |
| Weaknesses | CWE-434 CWE-646 CWE-79 |
|
| References |
| |
| Metrics |
cvssV3_1
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Projects
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Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-05-15T21:26:54.790Z
Reserved: 2026-05-11T20:50:30.538Z
Link: CVE-2026-45315
No data.
Status : Received
Published: 2026-05-15T22:16:54.250
Modified: 2026-05-15T22:16:54.250
Link: CVE-2026-45315
No data.
OpenCVE Enrichment
Updated: 2026-05-15T23:30:10Z
Github GHSA