CVE-2026-54009 Open WebUI: Cross-user file disclosure via /api/chat/completions image_url field
Authenticated users can access other users' files by manipulating image URLs, leading to unauthorized data disclosure.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-54009?
CVE-2026-54009 is a medium-severity missing authorization vulnerability in Openwebui Open Webui, published on 23 Jun 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6, POST /api/chat/completions accepts an image_url.url value that, when it does NOT start with http://, https://, or data:image/, is interpreted as a file id and resolved against the global file table with no ownership check. an authenticated user can therefore set image_url.url to another user's file id, the server reads that file from disk, base64-encodes it, and injects the data URI into the LLM request. the user then prompts the LLM to describe / OCR the file and reads the content back. This vulnerability is fixed in 0.9.6.
Weakness: CWE-639
Which versions are affected by CVE-2026-54009?
3 open source packages ship an affected version, including open-webui. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
open-webui PyPI | All versions | 0.9.6 |
open-webui PyPI | All versions | 0.9.6 |
open-webui PyPI | All versions | 0.9.6 |
Products include Openwebui Open Webui.
How do I fix CVE-2026-54009?
Upgrade open-webui to 0.9.6 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-54009 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-54009 exists.
Other vulnerabilities in Openwebui Open Webui
- CVE-2026-44551 Open WebUI: LDAP Empty Password Authentication Bypass
- CVE-2026-56400 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation
- CVE-2024-8017 Cross-site Scripting (XSS) in open-webui/open-webui
- CVE-2026-45672 Open WebUI: Jupyter code execution works despite `ENABLE_CODE_EXECUTION=false` — feature gate bypassed
- CVE-2026-87995 Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin
Sources
Also known as GHSA-wch8-mhj5-9frg, PYSEC-2026-2766.