EUVD-2026-75178

Open WebUI: Channel members can overwrite another member's message via the chat completions endpoint...

Open WebUI: Channel members can overwrite another member's message via the chat completions endpoint

Summary Any member of a channel who can post to it could also replace the text of a message written by a different member. The channel branch of the chat completions endpoint checked that the caller may write to the channel, and that the targeted message belongs to that channel, but never checked...

Missing Authorization

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Missing Authorization through the chat completions process. An attacker can overwrite another user's message content by submitting a crafted request to the endpoint, causing the original message to be replace...

GHSA-FMQH-XP37-5HR8 Open WebUI: Channel members can overwrite another member's message via the chat completions endpoint

Summary Any member of a channel who can post to it could also replace the text of a message written by a different member. The channel branch of the chat completions endpoint checked that the caller may write to the channel, and that the targeted message belongs to that channel, but never checked...

EUVD-2026-75179

Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin...

Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin

Summary Any authenticated user with access to a shared terminal server could get script of their choosing to run in the Open WebUI origin itself. The in-app port preview rendered the content of a previewed port in an iframe whose sandbox always granted allow-same-origin alongside allow-scripts, a...

Improper Restriction of Rendered UI Layers or Frames

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Improper Restriction of Rendered UI Layers or Frames in the PortPreview process. An attacker can gain access to session tokens and take over user accounts by serving malicious scripts on a terminal server por...

GHSA-JMC6-2WR8-H3WJ Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin

Summary Any authenticated user with access to a shared terminal server could get script of their choosing to run in the Open WebUI origin itself. The in-app port preview rendered the content of a previewed port in an iframe whose sandbox always granted allow-same-origin alongside allow-scripts, a...

GHSA-4V28-J6Q3-5M4R Open WebUI: SSRF into internal services via DNS rebinding in the Playwright web loader

Summary With the Playwright web loader enabled, Open WebUI checks the address behind a user-submitted URL before allowing the request, then handed the request to the browser to perform. The browser resolved the hostname a second time, on its own, and that answer was never checked. An attacker who...

EUVD-2026-75180

Open WebUI: SSRF into internal services via DNS rebinding in the Playwright web loader...

Open WebUI: SSRF into internal services via DNS rebinding in the Playwright web loader

Summary With the Playwright web loader enabled, Open WebUI checks the address behind a user-submitted URL before allowing the request, then handed the request to the browser to perform. The browser resolved the hostname a second time, on its own, and that answer was never checked. An attacker who...

Server-side Request Forgery (SSRF)

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Server-side Request Forgery SSRF in the SafePlaywrightURLLoader process when the Playwright web loader engine is enabled. An attacker can access internal network resources and sensitive data by submitting a...

EUVD-2026-75181

Open WebUI: Any authenticated user can inject chats into another user's folder via chat completions...

Open WebUI: Any authenticated user can inject chats into another user's folder via chat completions

Summary The chat-completions endpoint reads a folder id out of the request body and saves the newly created chat into that folder without checking that the caller is allowed to write there. Any authenticated user who knows a folder's id can put a chat of their own into another user's folder,...

Missing Authorization

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Missing Authorization through the chat-completions process. An attacker can insert unauthorized chat entries into another user's folder by supplying a folder ID they do not have write access to. This allows t...

GHSA-3PF7-Q2G3-WJ28 Open WebUI: Any authenticated user can inject chats into another user's folder via chat completions

Summary The chat-completions endpoint reads a folder id out of the request body and saves the newly created chat into that folder without checking that the caller is allowed to write there. Any authenticated user who knows a folder's id can put a chat of their own into another user's folder,...

EUVD-2026-75183

Open WebUI: Non-admin users can delete admin-owned external knowledge connections via knowledge base deletion...

Open WebUI: Non-admin users can delete admin-owned external knowledge connections via knowledge base deletion

Summary External knowledge connections are created and owned by administrators, and are shared by every external knowledge base bound to them. Deleting an external knowledge base also removed that connection from the instance configuration, with no check on the caller's role and no check for othe...

Incorrect Authorization

Overview open-webui is an Open WebUI Affected versions of this package are vulnerable to Incorrect Authorization in the knowledge base delete handler process. An attacker can remove instance-wide configuration managed by administrators by sending a DELETE request to the relevant API endpoint with...

GHSA-2724-6CPJ-GF3V Open WebUI: Non-admin users can delete admin-owned external knowledge connections via knowledge base deletion

Summary External knowledge connections are created and owned by administrators, and are shared by every external knowledge base bound to them. Deleting an external knowledge base also removed that connection from the instance configuration, with no check on the caller's role and no check for othe...