LiteLLM auth bypass: a one-character token unlocked MCP tools

LiteLLM carried CVE-2026-59822, an improper authentication flaw where a failed token check returned an empty auth object, so any bearer token — even a single character — passed. Chained with CVE-2026-42271 and CVE-2026-48710 it yields unauthenticated remote code execution; the fix ships in version 1.84.0.

• CVE-2026-59822: empty auth object instead of rejection let any token through
• CVE-2026-42271 is command injection in the MCP stdio test endpoint
• CVE-2026-48710 is a Starlette host header bypass enabling path injection
• Fixed release is LiteLLM 1.84.0; flaw added to CISA KEV catalog