CVE-2026-59221 open-webui terminal proxy path traversal guard bypass via 9x encoded traversal

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 before 0.10.0, sanitizeproxypath in backend/openwebui/routers/terminals.py decoded proxy paths only eight times, allowing a nine-times percent-encoded ../ traversal value to pass normalization checks...