If you create an instance of a HTTPSClientSession without providing a Context (which is possible with the available constructors), then the SSLManager will cause a crash during destruction.

// crash
int main()
{
    Poco::Net::HTTPSClientSession session;
}

Note however if you manually shutdown the SSLManager before termination then the crash doesn't occur.

// no crash
int main()
{
    Poco::Net::HTTPSClientSession session;
    Poco::Net::SSLManager::instance().shutdown();
}