Regular expressions are complicated and can be hard to learn. On top of that, they can also be a security risk; writing the wrong pattern can open your application up to denial of service attacks. One token out of place and you invite in the dreaded ReDoS.

But how can a regular expression cause this? In this talk we’ll track down the patterns that can cause this trouble, explain why they are an issue and propose ways to fix them now and avoid them in the future. Together we’ll demystify these powerful search patterns and keep your application safe from expressions that behave in a way that is anything but regular.