Resource Confusion Vulnerability in Model Context Protocol Python SDK
CVE-2026-116684
6.8MEDIUM
What is CVE-2026-116684?
The Model Context Protocol Python SDK suffers from a resource-confusion vulnerability that arises due to improper bearer token validation. Specifically, when server-side bearer authentication settings do not independently validate the audience for tokens, an attacker can use a valid token from one server to gain unauthorized access to another server within the same authorization domain. This flaw is present in versions prior to 1.30.0 and 2.2.0. The issue has been addressed in the aforementioned versions, ensuring that tokens are appropriately validated to maintain the integrity of server access control.
Affected Version(s)
python-sdk >= 1.10.0, < 1.30.0 < 1.10.0, 1.30.0
python-sdk >= 2.0.0, < 2.2.0 < 2.0.0, 2.2.0