LiteLLM nested user_config parameter could bypass outbound destination checks

What happened

LiteLLM’s advisory describes server-side request forgery through a nested user_config parameter. A caller could place a destination override inside that object, bypassing validation that checked only the corresponding top-level fields.

Exploitation required a valid virtual key. The proxy could then make requests to internal or external hosts chosen by the caller, potentially reaching services the caller could not access directly.

The advisory lists releases through 1.83.8 as affected and 1.83.9 as patched. Update to a maintained release and review outbound destination controls. This is a LiteLLM request-validation issue, not a security incident in Claude merely because the proxy supports Anthropic models.

Read the original source.

Source references

• GIT
  github.com LiteLLM nested user_config parameter could bypass outbound destination checks