CVE-2026-54007: Open WebUI Cross-origin postMessage confirmation bypass

# CVE-2026-54007: Open WebUI Cross-origin postMessage confirmation bypass

https://gcdradar.vercel.app/incidents/cve-2026-54007-open-webui-cross-origin-postmessage-confirmat · AIR-2026-0774 · closed 2026-06-17

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-06-17
- AI role: Attack on AI
- Products: Open WebUI
- CVE ids: CVE-2026-54007
- CVSS: 7.1

## Summary

A vulnerability in Open WebUI allows external sites to trigger unauthorized prompt submission in victim sessions via cross-origin postMessage messages. This enables cross-site forced actions and model execution under victim privileges.

## What to do

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

## Latest updates

- 2026-06-23: CVE-2026-54007: Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. (https://nvd.nist.gov/vuln/detail/CVE-2026-54007)
- 2026-06-17: CVE-2026-54007: Open WebUI: Cross-origin postMessage confirmation bypass via action:submit (https://github.com/advisories/GHSA-3vv5-8xxp-4f55)

## Sources

- 2026-06-17 GitHub Advisory Database: CVE-2026-54007: Open WebUI: Cross-origin postMessage confirmation bypass via action:submit https://github.com/advisories/GHSA-3vv5-8xxp-4f55
- 2026-06-23 NVD: CVE-2026-54007: Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. https://nvd.nist.gov/vuln/detail/CVE-2026-54007

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