CVE-2026-44553: Open WebUI Auth Bypass Vulnerability

CVE-2026-44553 Overview

CVE-2026-44553 affects Open WebUI, a self-hosted artificial intelligence platform designed to operate entirely offline. The vulnerability allows users whose administrative roles have been revoked to retain admin privileges within their active Socket.IO sessions. Open WebUI versions prior to 0.9.0 fail to iterate the SESSION_POOL to disconnect affected sessions when administrative role changes or user deletions occur. The session remains valid for as long as the connection stays alive via automatic heartbeats. The flaw is fixed in version 0.9.0 and is categorized under [CWE-613] Insufficient Session Expiration.

Critical Impact
Revoked administrators can continue performing privileged operations through existing Socket.IO connections, undermining access control enforcement.

Affected Products

Open WebUI versions prior to 0.9.0
Self-hosted deployments using Socket.IO session management
Multi-tenant Open WebUI instances with administrative role management

Discovery Timeline

2026-05-15 - CVE-2026-44553 published to NVD
2026-05-19 - Last updated in NVD database

Technical Details for CVE-2026-44553

Vulnerability Analysis

The vulnerability stems from incomplete session invalidation logic in Open WebUI. When an administrator revokes another user's admin role or deletes a user account, the application updates the persistent user store. However, it does not iterate the in-memory SESSION_POOL that tracks active Socket.IO connections. Existing WebSocket sessions continue holding the cached administrative privileges granted at connection time.

Socket.IO clients maintain long-lived connections through periodic heartbeat packets. As long as the client keeps the connection alive, the cached privilege context persists. The user can continue invoking administrator-only Socket.IO events even after the database role change takes effect for new sessions.

The gap is exclusive to the Socket.IO session cache. REST API endpoints that re-evaluate authorization on each request are not affected by this caching weakness.

Root Cause

The root cause is insufficient session expiration on privilege state changes. Role and account modifications update authoritative storage but do not propagate to active Socket.IO sessions. The SESSION_POOL is never iterated to terminate or re-authorize sessions belonging to the affected user.

Attack Vector

An authenticated user with previously granted admin privileges maintains an open Socket.IO connection to the Open WebUI server. A higher-privilege administrator revokes their role or deletes the account. The attacker's Socket.IO session continues operating with administrative capabilities, allowing privileged actions such as configuration changes, user management, or model administration through Socket.IO events. Exploitation requires no special tooling beyond keeping the existing browser tab or client open.

The vulnerability requires low-privileged authenticated access and is exploitable over the network without user interaction.

Detection Methods for CVE-2026-44553

Indicators of Compromise

Administrative Socket.IO events originating from user accounts whose admin role was recently revoked
Long-lived WebSocket connections persisting after user deletion events in audit logs
Discrepancy between current user role in the database and privileged actions logged via Socket.IO
Heartbeat traffic from session identifiers tied to demoted or removed user accounts

Detection Strategies

Correlate user role change events with subsequent Socket.IO activity from the same user identifier
Audit SESSION_POOL membership against current user privileges to identify stale privileged sessions
Monitor for administrative Socket.IO event invocations following role revocation timestamps
Inspect WebSocket frame logs for privileged operations issued by non-admin accounts

Monitoring Recommendations

Enable verbose audit logging for all administrative Socket.IO event handlers in Open WebUI
Forward Open WebUI application logs to a centralized SIEM for cross-event correlation
Track Socket.IO connection duration metrics and alert on sessions persisting through role change events
Review authentication and authorization event timelines after each privilege change

How to Mitigate CVE-2026-44553

Immediate Actions Required

Upgrade Open WebUI to version 0.9.0 or later, which contains the fix
Restart the Open WebUI service after privilege changes to forcibly terminate active Socket.IO sessions until patched
Inventory all users with current or recent administrative privileges and validate their session state
Review the GitHub Security Advisory GHSA-45m8-cpm2-3v65 for vendor guidance

Patch Information

The Open WebUI maintainers released version 0.9.0 to address CVE-2026-44553. The fix ensures that role changes and user deletions iterate the SESSION_POOL and disconnect affected Socket.IO sessions. Operators should upgrade directly to 0.9.0 or later. Refer to the Open WebUI Security Advisory for release notes and remediation details.

Workarounds

Manually restart the Open WebUI server after every administrative role revocation or user deletion to clear the session pool
Place Open WebUI behind a reverse proxy configured to terminate WebSocket connections on a short idle timeout
Restrict administrative role assignment to a minimal set of trusted operators to reduce exposure window
Disable Socket.IO transport where feasible until the upgrade to 0.9.0 is completed

bash

# Upgrade Open WebUI via Docker
docker pull ghcr.io/open-webui/open-webui:0.9.0
docker stop open-webui
docker rm open-webui
docker run -d --name open-webui \
  -p 3000:8080 \
  -v open-webui:/app/backend/data \
  ghcr.io/open-webui/open-webui:0.9.0