Passenger 5.3.2 was just released, fixing a file system access race condition [CVE-2018-12029] as well as various SpawningKit exploits [CVE-2018-12026 - 12027 - 12028]. We urge you to upgrade your version immediately. The release notes contain more information on the measures we’ve taken to recognize security flaws quicker in the future: https://blog.phusion.nl/2018/06/12/passenger-5-3-2-various-security-fixes/