WordPress 3.7 was released on October 24, 2013 and introduced an automatic update mechanism to ensure security fixes would be automatically deployed on all WordPress sites, in an effort to prevent recently-patched vulnerabilities from being massively exploited in the wild. This is widely regarded by security experts as a good idea.
However, the WordPress automatic update feature had one glaring Achilles’ heel: If a criminal or nation state were to hack into the WordPress update server, they could trigger a fake automatic update to infect WordPress sites with malware.
This isn’t just a theoretical concern, it could have happened if not for WordFence’s security researchers finding and disclosing an easy attack vector into their infrastructure.
WordPress 5.2 was released on May 7, 2019 and provides the first real layer of defense against a compromised update infrastructures: offline digital signatures.