they exist, but they are likely unmaintained, and may have known security issues.

i have a project that suffers from that. the version of a library it is built with is old and unsecure, but the newer supported version has a completely different API that would require me to rewrite the code that uses the library.

i had a second such case where i discovered a fork of the old version of the library which was still maintained. otherwise there too a rewrite would have been required.