Ransomware groups are hammering your vulnerable VPNs

Ransomware groups are exploiting a critical authentication bypass flaw, CVE-2026-0257, in Palo Alto Networks' GlobalProtect portal and gateway to deploy the Qilin ransomware strain. This vulnerability was quickly leveraged by cybercriminals, with exploitation occurring within days of its disclosure. The flaw allows attackers to bypass authentication mechanisms, granting them unauthorized access to vulnerable VPNs and firewalls. Arctic Wolf Labs has identified a series of intrusions in June that utilized this exploit, resulting in varying degrees of post-exploitation tradecraft, including rapid encryption and double-extortion tactics¹. The swift exploitation of this vulnerability highlights the importance of prompt patching and monitoring. So what matters to practitioners is that the active exploitation of CVE-2026-0257 necessitates immediate attention to determine whether a patch-now or monitor approach is required to prevent Qilin ransomware infections.