CVE-2026-0257 flaw lets hackers bypass Palo Alto VPN auth

A critical vulnerability (CVE-2026-0257) in Palo Alto Networks' PAN-OS GlobalProtect VPN allows attackers to bypass authentication and gain unauthorized access to VPNs. Disclosed in May 2026, the flaw has been actively exploited, prompting advisories from cybersecurity organizations, including the CISA. The issue arises from the misuse of authentication override cookies and specific certificate configurations.

Researchers recommend immediate patching of vulnerable devices and urge organizations to treat this vulnerability as critical due to its potential impact on network security.