The latest Magento 1 security patch SUPEE-8788 contains [17 APPSEC updates](https://magento.com/security/patches/supee-8788), so it is very important to apply it as soon as possible. On the other hand, these are many potential BC breaks, and given the history of patches over the last year I would not apply it carelessly.

Good thing is that this time there are no frontend templates involved, so it looks like we don't need to patch all our themes.

Nonetheless: Did you encounter any compatibility problems or bugs after applying the patch?