Disclosed weakness · no CVE recorded

LiteLLM could silently omit a configured MCP guardrail

LiteLLM · LiteLLM Proxy

First documented disclosure · Review checkpoint

Summary

An operator could enable checks for MCP tool calls while the gateway continued handling those calls without the configured protection.

Severity and exploitation evidence

No CVSS score recorded in this review.

Exploitation not established: The original source establishes the weakness but does not report malicious exploitation.

Exploitation evidence source

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

The generic guardrail integration failed to attach configured MCP call checks at startup.

Conditions required

The deployment uses a generic guardrail configured for MCP tool calls.

Potential impact

Tool calls could proceed without the operator’s intended pre-call, in-call or post-call controls.

Affected versions and configurations

The affected behavior is documented. The full version range is not established.

Fix and mitigation status

1.109.0 lists this correction; other release lines may differ.

Practical next steps

Use a release containing this correction. Check that expected guardrails were loaded and exercised for each protected tool.

Operating lesson

Make missing policy integrations visible when the service starts.

Evidence and limits

The project describes the correction in the linked public changes and lists it in 1.109.0. No CVE assignment or complete affected range was established.

Sources