What’s Vulnerable › Vulnerabilities

CVE-2026-70486: Open WebUI: Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-08-04 · updated 2026-09-18
• Weakness: CWE-79

Description

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

• open-webui: from 0.9.0 before 0.11.0 — fixed in 0.11.0

How to fix

Upgrade to a fixed version: open-webui 0.11.0. Check the vendor advisory for mitigations.

References

• https://github.com/open-webui/open-webui/commit/65a5fad7b97db99d490d81f4e0860282c3a4543c
• https://github.com/open-webui/open-webui/pull/26907
• https://github.com/open-webui/open-webui/releases/tag/v0.11.0
• https://github.com/open-webui/open-webui/security/advisories/GHSA-3xpf-xq7r-v8c5

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