CVE-2026-27124 (GCVE-0-2026-27124)
Vulnerability from cvelistv5
Published
2026-04-03 15:22
Modified
2026-04-03 16:44
CWE
  • CWE-441 - Unintended Proxy or Intermediary ('Confused Deputy')
Summary
FastMCP is the standard framework for building MCP applications. Prior to version 3.2.0, while testing the GitHubProvider OAuth integration, which allows authentication to a FastMCP MCP server via a FastMCP OAuthProxy using GitHub OAuth, it was discovered that the FastMCP OAuthProxy does not properly validate the user's consent upon receiving the authorization code from GitHub. In combination with GitHub’s behavior of skipping the consent page for previously authorized clients, this introduces a Confused Deputy vulnerability. This issue has been patched in version 3.2.0.
Impacted products
Vendor Product Version
jlowin fastmcp Version: < 3.2.0
Create a notification for this product.
Show details on NVD website


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