n8n versions before 1.123.69, 2.33.4, and 2.34.1 contain an information disclosure vulnerability in the GraphQL node. When a GraphQL request fails at the connection level, the node re-throws the underlying HTTP client error unchanged instead of wrapping it in n8n's standard error type. That error contains the live request's headers, including a decrypted credential secret, which the execution engine persists verbatim. Any authenticated user able to read the resulting execution can retrieve the decrypted credential secret from the stored run data.