CVE-2026-45315

8.7 HIGH 0.2% exploit odds Fix listed XSS Device

What it is

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.

At a glance

Exploitability: Can be exploited over the network with a low-privilege account, but needs a user to act. High risk of data exposure, data tampering.
Exploit odds: 0.2% chance of exploitation in the next 30 days (EPSS).
Fix: A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

2026-05-15 22:16 UTC PublishedDisclosed publicly on CVE.org and NVD
2026-06-17 10:51 UTC Last updatedMost recent change to the record

Why it ranks here

Exploited in the wild: no, CISA does not list it.
Exploit odds: 0.2% in the next 30 days (EPSS).
Severity: 8.7 HIGH (CVSS).
Fix: a patch or advisory is linked.

Details

Published: 2026-05-15 22:16 UTC
Last modified: 2026-06-17 10:51 UTC
Exploit probability: 0.2% · EPSS, next 30 days
Weakness: CWE-79 · Cross-site scripting
Record status: Modified

Affected

Openwebui Open Webui < 0.9.3

Attack profile CVSS 3.1 · 8.7

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: Required
Scope: Changed
Confidentiality: High
Integrity: High
Availability: None

Raw vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2026-45315.md and follow it. Check whether this project is affected by CVE-2026-45315. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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Fix and advisories

References

NVD record · CVE.org record