Palo Alto Networks has fixed a vulnerability in the GlobalProtect portal and gateway components of PAN-OS. An unauthenticated attacker can exploit the vulnerability to establish a VPN connection, gaining access to internal systems. Systems are only vulnerable when HTTPS certificates are reused and specific authentication override options are enabled. Rapid7 reports the vulnerability is being actively exploited, and proof-of-concept code is publicly available. The NCSC expects the scale of exploitation to increase in the coming period.