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TI-2026-33114 Aliases CVE-2026-45315GHSA-m8f9-9whg-f4xr

Open WebUI: Stored XSS via attacker-controlled file extension in /api/v1/audio/transcriptions

Priority HIGH 73CWE-434Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Required
Attack complexity
Low
Impact type
Code execution, Cross-site scripting
Confidentiality · integrity · availability
High · High · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-434 and CWE-79.

Summary

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.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00186 8th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed open-webui (open-webui): 0.9.3open-webui (PyPI): 0.9.3

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
open-webuiopen-webuibefore 0.9.30.9.3Patch availableCNA
—open-webui (PyPI)before 0.9.30.9.3Patch availableGHSA-m8f9-9whg-f4xr
  • open-webui Vendoropen-webui Affected before 0.9.3 Fixed in 0.9.3 Patch available CNA
  • open-webui (PyPI) Vendor— Affected before 0.9.3 Fixed in 0.9.3 Patch available GHSA-m8f9-9whg-f4xr

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*before 0.9.3Vulnerableopen-webui
  • cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:* Versions before 0.9.3 Vulnerable ·open-webui

Remediation

  • Fix · CNA open-webui (open-webui) Fixed in 0.9.3
  • Fix · GHSA-m8f9-9whg-f4xr open-webui (PyPI) Fixed in 0.9.3 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-45315
  2. 2026-10-03 Alias added: GHSA-m8f9-9whg-f4xr

References

Exploit 1

Advisory 1

Other 2

  • TI-2024-06216 Open WebUI Arbitrary File Upload + Path Traversal CVSS 3.1HIGH 8.8
  • TI-2024-07467 Improper Authentication in open-webui/open-webui CVSS 3.1HIGH 8.2
  • TI-2026-42359 Open WebUI: Cross-user code-interpreter and tool execution via unvalidated Socket.IO event-caller session_id CVSS 3.1CRITICAL 9.0
  • TI-2026-40759 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation CVSS 4.0CRITICAL 9.0
  • TI-2024-07431 Cross-site Scripting (XSS) in open-webui/open-webui CVSS 3.0CRITICAL 9.0
  • TI-2026-60021 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin CVSS 3.1HIGH 8.7
See all 154 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences