Ask HN: Can a PHP RCE vulnerability auto-patch vulnerable servers?

A question was posed about whether a PHP remote code execution vulnerability could be used to automatically patch vulnerable servers before they are exploited. The idea is that a proof of concept could potentially detect vulnerable installations, apply a security fix, and verify the patch's success. Technical and practical obstacles that might prevent this approach from working safely at scale were also queried. The question was asked on Hacker News, a forum for discussing technology and related topics. No comments have been made on the question yet. The inquiry seeks to explore the theoretical possibility of using a vulnerability for self-patching purposes.