CVE-2026-110195

MCP token caching could mix credentials for the same user

IBM · ContextForge MCP Gateway token exchange cache

First documented disclosure · Review checkpoint

Summary

The cache key failed to distinguish the credentials a user presented during upstream token exchange. A call could reuse an upstream token with permissions assigned to another credential of that user.

Severity and exploitation evidence

Medium · 5.4/10 · CVSS 3.1. Severity source.

Exploitation not established: The reviewed advisory 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 cache key failed to distinguish the credentials a user presented during upstream token exchange.

Conditions required

One user had different credentials with different upstream authorization policies.

Potential impact

A call could reuse an upstream token with permissions assigned to another credential of that user.

Affected versions and configurations

1.0.0 through 1.0.11.

Fix and mitigation status

1.1.0.

Practical next steps

Upgrade and review upstream permissions assigned to different credential types for the same user.

Operating lesson

Key cached authorizations on the credential and policy that produced them.

Evidence and limits

The advisory and CVE record were published on 2026-11-13.

Sources