Researchers and threat hunters are scrambling to respond to an actively exploited authentication-bypass vulnerability affecting Palo Alto Networks customers’ firewalls.  The company initially tagged CVE-2026-0257 with a medium-severity rating when it disclosed the defect May 13, but quickly reassessed it as critical after Rapid7 observed and confirmed active exploitation in the wild. The Cybersecurity and Infrastructure Security Agency followed suit, and added the vulnerability to its known