Cisco Patches Second Firewall VPN Zero-Day Since August

Cisco released fixes for CVE-2026-76418 (CVSS 8.6), an exploited flaw in the Remote Access SSL VPN service of Secure Firewall ASA and FTD. Unauthenticated attackers can remotely force a device restart; the bug was exploited in the wild. It is the second ASA/FTD zero-day used for DoS attacks since August.

• CVE-2026-76418: CVSS 8.6, logic errors in tunnel groups with secondary authentication
• No successful VPN login needed, but SSL VPN must be reachable on an unpatched release
• Cloud-delivered firewalls, Secure Access and Management Center are not vulnerable
• No workarounds; disabling secondary auth weakens security, Cisco recommends upgrading