Let's Encrypt cuts certificate lifetimes to 64 days starting February 2027

Ars Technica security RSS digest covering active exploitation, certificate and registry compromise, AI-agent security weaknesses, ransomware and data breaches, exploit kits, social-engineering campaigns, surveillance-camera exposure, and emerging cryptographic risks. The most urgent items include exploitation of a critical Zimbra flaw for email theft, counterfeit TLS certificates obtained through compromised domain registries, a serious zero-day affecting Meta’s Muse agent, widespread ClickFix infections, and a Chrome/Windows exploit kit used by multiple threat groups.