Open WebUI server hang via cyclic chat message history

# Open WebUI server hang via cyclic chat message history

https://gcdradar.vercel.app/incidents/open-webui-server-hang-via-cyclic-chat-message-history · AIR-2026-0906 · closed 2026-09-09

- Lane: Patch now
- Severity: 2 (Disclosed vulnerability)
- Fix status: Fix status unknown
- First reported: 2026-09-09
- AI role: Attack on AI
- Products: Open WebUI
- CVE ids: CVE-2026-88002
- CVSS: 6.5

## Summary

A failure to track visited nodes during message chain reconstruction allowed users to trigger infinite loops with malformed message histories. The resulting unbounded server walk blocks functionality for all users.

## What to do

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

## Latest updates

- 2026-09-09: CVE-2026-88002: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. (https://nvd.nist.gov/vuln/detail/CVE-2026-88002)
- 2026-09-09: CVE-2026-88002: Open WebUI: Any authenticated user can hang the server via a cyclic chat message history (https://github.com/advisories/GHSA-jqhh-cjmq-vmv6)

## Sources

- 2026-09-09 GitHub Advisory Database: CVE-2026-88002: Open WebUI: Any authenticated user can hang the server via a cyclic chat message history https://github.com/advisories/GHSA-jqhh-cjmq-vmv6
- 2026-09-09 NVD: CVE-2026-88002: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. https://nvd.nist.gov/vuln/detail/CVE-2026-88002

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