CVE-2026-87995: Open WebUI XSS via terminal port-preview iframe sandbox misconfiguration

# CVE-2026-87995: Open WebUI XSS via terminal port-preview iframe sandbox misconfiguration

https://gcdradar.vercel.app/incidents/cve-2026-87995-open-webui-xss-via-terminal-port-preview-ifra · AIR-2026-0929 · closed 2026-09-09

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-09-09 (happened 2026-09-10)
- AI role: Attack on AI
- Products: Open WebUI
- CVE ids: CVE-2026-87995
- CVSS: 8.7

## Summary

An overly permissive iframe sandbox in Open WebUI allowed scripts from terminal port previews to access the application origin, enabling session token theft. Patches are available to resolve the isolation issue.

## What to do

No action recorded; read the sources below and the vendor's advisory.

## Latest updates

- 2026-09-10: CVE-2026-87995: Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin (https://github.com/advisories/GHSA-jmc6-2wr8-h3wj)
- 2026-09-09: CVE-2026-87995: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. (https://nvd.nist.gov/vuln/detail/CVE-2026-87995)

## Sources

- 2026-09-09 NVD: CVE-2026-87995: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. https://nvd.nist.gov/vuln/detail/CVE-2026-87995
- 2026-09-10 GitHub Advisory Database: CVE-2026-87995: Open WebUI: Same-origin XSS to account takeover via terminal port-preview iframe hardcoding allow-same-origin https://github.com/advisories/GHSA-jmc6-2wr8-h3wj

Verify against the vendor's advisory before changing production. Data CC BY-SA 4.0, https://gcdradar.vercel.app.