Improper Authentication

Overview Affected versions of this package are vulnerable to Improper Authentication through the validateOpaqueToken process. An attacker can gain unauthorized access to protected tools and underlying data sources by submitting an OAuth 2.0 introspection response that omits the mandatory active...

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...

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...

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...

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...