CVE-2026-116684

medium

Description

The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.10.0 until 1.30.0 and 2.2.0, server-side bearer authentication configured through AuthSettings with token_verifier accepts a valid token issued for another service when the authorization server serves multiple resources and the TokenVerifier does not independently validate the aud audience. This resource-confusion flaw lets a token holder authenticate to the wrong MCP server and exercise that token's resulting access. This issue is fixed in versions 1.30.0 and 2.2.0.

References

https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23

https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0

https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0

https://github.com/modelcontextprotocol/python-sdk/pull/3451

https://github.com/modelcontextprotocol/python-sdk/pull/3447

https://github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512

https://github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-111369

Details

Source: Mitre, NVD

Published: 2026-10-27

Updated: 2026-10-27

Risk Information

CVSS v2

Base Score: 6.6

Vector: CVSS2#AV:N/AC:H/Au:S/C:C/I:C/A:N

Severity: Medium

CVSS v3

Base Score: 6.8

Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N

Severity: Medium