On October 20, CVE identifiers for two critical vulnerabilities in PHP began circulating on Hacker News and social media. Later that day, the PHP security team published an advance notice of an emergency security release scheduled for October 21 at 14:00 UTC. Public reporting describes both as remote code execution vulnerabilities, and a video credited to researcher LCFR and Calif.io demonstrates an exploit chain dubbed php2shell.

Cloudflare CTO Dane Knecht said the company is seeing early attacks emerging.

For more information about the vulnerabilities, including the availability of patches and Tenable product coverage, please visit our blog.