GHSA-8FCC-W5HV-4GXV googleapis/mcp-toolbox: authentication bypass vulnerability in the generic opaque token validation path (validateOpaqueToken)

An authentication bypass vulnerability exists in the generic opaque token validation path validateOpaqueToken of googleapis/mcp-toolbox. When verifying an unparsed opaque token via an OAuth 2.0 introspection endpoint RFC 7662, the toolbox decodes the response into an introspectResp struct where t...

CVE-2026-11717

An authentication bypass vulnerability exists in the generic opaque token validation path validateOpaqueToken of googleapis/mcp-toolbox. When verifying an unparsed opaque token via an OAuth 2.0 introspection endpoint RFC 7662, the toolbox decodes the response into an introspectResp struct where t...

EUVD-2026-37879

An authentication bypass vulnerability exists in the generic opaque token validation path validateOpaqueToken of googleapis/mcp-toolbox. When verifying an unparsed opaque token via an OAuth 2.0 introspection endpoint RFC 7662, the toolbox decodes the response into an introspectResp struct where t...