CVE-2026-70486: Open WebUI file-preview iframe vulnerability leads to account takeover

# CVE-2026-70486: Open WebUI file-preview iframe vulnerability leads to account takeover

https://gcdradar.vercel.app/incidents/cve-2026-70486-open-webui-file-preview-iframe-vulnerability · AIR-2026-0044 · closed 2026-08-04

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-08-04
- AI role: Attack on AI
- Products: Open WebUI
- CVE ids: CVE-2026-70486
- CVSS: 8.2

## Summary

An iframe permission flaw in Open WebUI enables authenticated users to execute scripts in the application origin and steal session tokens. The vulnerability is addressed through software patches without confirmed exploitation.

## What to do

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

## Latest updates

- 2026-08-04: CVE-2026-70486: Open WebUI: Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin (https://github.com/advisories/GHSA-3xpf-xq7r-v8c5)
- 2026-08-04: CVE-2026-70486: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. (https://nvd.nist.gov/vuln/detail/CVE-2026-70486)

## Sources

- 2026-08-04 NVD: CVE-2026-70486: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. https://nvd.nist.gov/vuln/detail/CVE-2026-70486
- 2026-08-04 GitHub Advisory Database: CVE-2026-70486: Open WebUI: Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin https://github.com/advisories/GHSA-3xpf-xq7r-v8c5

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