Ask HN: Open source security projects seeking for contribution

I am looking for open source projects with focus on security to contribute to. I am no security person but I wanted to learn about security and from times to times I want to give back some of what I took from open source community. I would prefer to contribute to security because it seems to be one of major and most problematic parts of software world. I also like to start with simple bite-size bugs/issues/features.

tl;dr Are there any open source security projects with bite-size issues to fix?