When sending data to an MQTT server, libcurl <= 7.73.0 and 7.78.0 could in some circumstances erroneously keep a pointer to an already freed memory area and both use that again in a subsequent call to send data and also free it *again*.

{
                    "vendor": "n/a",
                    "product": "https://github.com/curl/curl",
                    "versions": [
                        {
                            "version": "curl 7.73.0 to and including 7.78.0",
                            "status": "affected"
                        }
                    ]
                }