CVE-2024-5642 Buffer overread when using an empty list with SSLContext.set_npn_protocols()

CPython 3.9 and earlier doesn't disallow configuring an empty list "" for SSLContext.setnpnprotocols which is an invalid value for the underlying OpenSSL API. This results in a buffer over-read when NPN is used see CVE-2024-5535 for OpenSSL. This vulnerability is of low severity due to NPN being...