CVE-2026-45315
Open WebUI: Stored XSS via attacker-controlled file extension in /api/v1/audio/transcriptions
- Published
- Updated
- Reserved
- Assigned by
- GitHub_M
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.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High8.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
| NVDNVD · Modified | 3.1 | High8.7 | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.19% · top 92% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: poc · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.7.
Weakness
- CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (opens in a new tab)All about CWE-79 and its CVEs
- CWE-434: Unrestricted Upload of File with Dangerous Type (opens in a new tab)All about CWE-434 and its CVEs
- CWE-646: Reliance on File Name or Extension of Externally-Supplied File (opens in a new tab)All about CWE-646 and its CVEs
Affected products
- affected < 0.9.3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- PyPIopen-webuiGHSA-m8f9-9whg-f4xr (opens in a new tab)
References (1)
- https://github.com/open-webui/open-webui/security/advisories/GHSA-m8f9-9whg-f4xr (opens in a new tab)x_refsource_CONFIRMexploit
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-m8f9-9whg-f4xr (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-45315)Record last updated .