CVE-2026-70486 Details
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.
A cross-site scripting vulnerability has been identified in Open WebUI versions 0.9.0 prior to 0.11.0. The issue arises in the terminal file-preview feature, where HTML files served from the application origin are rendered in an iframe with a sandbox that always allows scripts to run and access the same-origin context. This flaw enables an authenticated user with access to a terminal server to execute scripts in the Open WebUI origin, potentially leading to account takeover by exfiltrating the victim's session token from localStorage. If the compromised account belongs to an admin or has workspace.functions, it could also result in server-side code execution.
Users can upgrade to Open WebUI version 0.11.0, which fixes the vulnerability by ensuring that the `serveUrl` preview branch does not automatically grant same-origin access. No additional configuration is required.
Metrics
CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Aug 5, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/open-webui/open-webui/commit/65a5fad7b97db99d490d81f4e0860282c3a4543c | [email protected] | Patch |
| https://github.com/open-webui/open-webui/pull/26907 | [email protected] | PatchVendor Advisory |
| https://github.com/open-webui/open-webui/releases/tag/v0.11.0 | [email protected] | Release Notes |
| https://github.com/open-webui/open-webui/security/advisories/GHSA-3xpf-xq7r-v8c5 | [email protected] | ExploitPatchVendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-1021 | Improper Restriction of Rendered UI Layers or Frames | [email protected] |
| CWE-79 | Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| openwebui open webui | >= 0.9.0, < 0.11.0 |
CPE
Remediation
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Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 18, 2026 | Initial Analysis | [email protected] |
| Aug 5, 2026 | CVE Modified | CISA-ADP |
| Aug 4, 2026 | New CVE Received | [email protected] |