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-2026-11718

The CVE-2026-11718 entry concerns an authentication bypass in googleapis/mcp-toolbox: during opaque-token validation via an OAuth 2.0 introspection endpoint, the code decodes the response and checks issuer with the condition a.issuer != "" && iss != "". If the introspection response omits iss, is...

CVE-2026-11718

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

PT-2026-50660

Name of the Vulnerable Software and Affected Versions googleapis/mcp-toolbox affected versions not specified Description An authentication bypass exists in the generic opaque token validation path validateOpaqueToken. When validating an opaque token via an OAuth 2.0 introspection endpoint, the...