DEV Community

CVE Reports
CVE Reports

Posted on Originally published at cvereports.com

CVE-2026-88000: CVE-2026-88000: Denial of Service via Infinite Loop in Open WebUI Chat History Deletion

#security #cve #cybersecurity

CVE-2026-88000: Denial of Service via Infinite Loop in Open WebUI Chat History Deletion

Vulnerability ID: CVE-2026-88000
CVSS Score: 6.5
Published: 2026-09-09

An authenticated denial-of-service vulnerability exists in Open WebUI versions 0.10.0 up to 0.11.0. By uploading a malformed chat history containing cyclical child message references and requesting a message deletion, an attacker can trigger an infinite loop. Since Open WebUI relies on Python's single-threaded asyncio event loop, the CPU-bound loop blocks all incoming connections, freezing the service for all users.

TL;DR

An authenticated user can permanently freeze an Open WebUI server by creating a circular message reference and initiating a deletion, causing an infinite CPU-bound loop that blocks the application's single asyncio thread.

⚠️ Exploit Status: POC

Technical Details

  • CWE ID: CWE-835
  • Attack Vector: Network (AV:N)
  • CVSS v3.1 Score: 6.5
  • EPSS Score: Not available
  • Impact: High Availability Impact (Complete Denial of Service)
  • Exploit Status: Proof of Concept
  • KEV Status: Not Listed

Affected Systems

  • Self-hosted Open WebUI installations utilizing message history APIs
  • open-webui: >= 0.10.0, < 0.11.1 (Fixed in: 0.11.1)

Code Analysis

Commit: b933292

Add cycle-detection utilizing a visited tracking set to break out of infinite loops during chat history current ID resolution.

Exploit Details

  • Advisory: Proof of Concept structural overview detailing the payload creation of cyclic child dependencies and triggering of the deletion endpoint.

Mitigation Strategies

  • Upgrade to version 0.11.1 or later
  • Restrict user registration to trusted identities
  • Implement API rate limiting on chat management endpoints
  • Configure process health monitors to auto-restart frozen containers

Remediation Steps:

  1. Pull the latest secure Docker image using: docker pull ghcr.io/open-webui/open-webui:main
  2. Stop the existing container deployment.
  3. Remove the vulnerable container instance while keeping the persistent data volumes.
  4. Recreate and run the container with the updated image release.
  5. Verify the software version in the administrative control panel.

References

Read the full report for CVE-2026-88000 on our website for more details including interactive diagrams and full exploit analysis.

Top comments (0)