I've posted this once before but it failed to get traction. I'm reposting this with the permission of HN admins.
In a nutshell: This open-source project provides a framework for fuzzing cryptographic libraries. It can find both memory bugs and implementation errors. So far it has found about 35 bugs of varying severity in the stable releases of major cryptographic libraries. The fuzzers run continually on Google's OSS-Fuzz platform which helps detect bugs before they end up in stable releases.
The article describes the technical details of the software. Here you can find a summary of the bugs it has found: https://github.com/guidovranken/cryptofuzz#hall-of-fame