CVE-2026-44553 open-webui CVE debrief

Who should care

Organizations operating self-hosted Open WebUI instances with multiple administrative users or automated provisioning workflows; security teams managing identity lifecycle processes; compliance officers evaluating access control audit trails for administrative function separation.

Technical summary

The vulnerability stems from incomplete session lifecycle management in Open WebUI's Socket.IO implementation. When administrative role changes or user deletions occur through the application API, the SESSION_POOL data structure—responsible for tracking active Socket.IO connections and their associated privilege contexts—is not traversed to terminate or update affected sessions. The Socket.IO transport maintains connections via automatic heartbeat packets, preventing natural session expiration. Consequently, the session layer retains stale authorization metadata while the persistence layer reflects updated access controls. This architectural gap creates a time-of-check to time-of-use (TOCTOU) condition where authentication decisions are decoupled from ongoing authorization validation. The fix in 0.9.0 introduces session pool iteration logic triggered by privilege modification events, ensuring session state consistency with the authoritative user store.

Defensive priority

HIGH

Recommended defensive actions

• Upgrade Open WebUI to version 0.9.0 or later to obtain the session invalidation fix
• Review administrative user access logs for anomalous extended session durations preceding the upgrade date
• Implement session timeout policies and connection limits to reduce window of opportunity for stale privilege exploitation
• Monitor Socket.IO connection patterns for sessions persisting beyond expected user lifecycle events
• Validate that role change workflows in integrated identity systems trigger application-level session termination where API hooks are available

Evidence notes

Vendor advisory confirms exploitability and provides fixed version. CVSS 3.1 vector AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N aligns with network-accessible, low-complexity attack requiring prior authentication. CPE range confirms all versions below 0.9.0 affected.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.