CVE-2026-87995: open-webui Cross-site Scripting

Vulnerability summary

CVE-2026-87995 is a high (CVSS 8.7) Cross-site Scripting vulnerability in open-webui. EPSS estimates a 0.42% chance of exploitation in the next 30 days, higher than 34.8% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 09-09-2026
   PublishedVulnerability first disclosed.
2. 10-09-2026
   Last modifiedVulnerability information updated.

Description

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.11 until 0.11.1, src/lib/components/chat/FileNav/PortPreview.svelte rendered terminal port content in an iframe sandbox containing both allow-scripts and allow-same-origin. Because the terminal proxy serves that content from the Open WebUI origin, an authenticated user with access to a shared terminal server could host script on a previewed port and take over a victim's account when the victim opened the preview. This issue is fixed in version 0.11.1.

• CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
• CWE-1021Improper Restriction of Rendered UI Layers or FramesThe web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain.