CVE-2026-35029: LiteLLM: Privilege escalation via unrestricted proxy configuration endpoint

The /config/update endpoint does not enforce admin role authorization. A user who is already authenticated into the platform can then use this endpoint to do the following:

• Modify proxy configuration and environment variables
• Register custom pass-through endpoint handlers pointing to attacker-controlled Python code, achieving remote code execution
• Read arbitrary server files by setting UI_LOGO_PATH and fetching via /get_image
• Take over other priveleged accounts by overwriting UI_USERNAME and UI_PASSWORD environment variables