CallingSSL_COMP_free_compression_methods();aftercurl_global_cleanup();appears to fix the problem. See also#2561: Memory leak with SSL built-in compressions curl/libcurl version curl 7.48.0 (i386-pc-win32) libcurl/7.48.0 OpenSSL/1.0.2h zlib/1.2.8 WinIDN Protocols: dict file ftp ftps goph...