curl: CURLSHOPT_UNSHARE race can cause UAF in shared SSL session cache during HTTPS transfer_H1:3831345
## Summary `CURLSHOPT_UNSHARE` can free a shared SSL session cache while another thread is starting a normal HTTPS transfer with the same share handle. The failing transfer reaches the cache through `curl_easy_perform()`, during the OpenSSL handshake. libcurl appears to try t...