CVE-2026-70486: Openwebui Open Webui

Medium severity, CVSS 5.4. EPSS: 0.4% chance of exploitation in the next 30 days.

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, the terminal file-preview serveUrl iframe branch always granted allow-same-origin together with allow-scripts for HTML files served from the application origin. Any authenticated user with access to a configured terminal server could cause script in a previewed file to run in the Open WebUI origin, read the victim's session token from localStorage, and take over the account, with possible server-side code execution if the victim was an admin or held workspace.functions. This issue is fixed in 0.11.0.

Affected products

• Openwebui Open Webui: from 0.9.0, before 0.11.0 (fixed in 0.11.0)

Published 2026-08-04. Last modified 2026-09-18.