CVE-2026-59819: LiteLLM: Local file read via request-supplied OIDC file references

LiteLLM’s /health/test_connection endpoint resolved request-supplied environment and OIDC file references in litellm_params. A proxy administrator, or another privileged caller with permission to test model connections, could cause LiteLLM to read files from the local filesystem via an oidc/file/ reference.

Because exploitation requires privileged proxy access, this is treated as a defense-in-depth issue rather than a cross-tenant privilege bypass.