CVE-2026-76418 with a CVSS score of 8.6 is a remote denial-of-service vulnerability in the Remote Access SSL VPN service of Cisco Secure Firewall Adaptive Security Appliance (ASA) and Threat Defense (FTD) software. The flaw is caused by logic errors in the SSL VPN processing path when secondary authentication is enabled on a tunnel group. An unauthenticated remote attacker can exploit it by sending a crafted request while connecting to the SSL remote access VPN, without needing a successful VPN login. The affected processing path is reachable when the webvpn keyword is enabled on at least one interface and secondary-authentication-server-group is configured on any tunnel group or on DefaultWEBVPNGroup. A successful exploit forces the firewall to reload, creating a persistent denial-of-service condition. Because these appliances commonly function as perimeter firewalls and VPN gateways for enterprise networks, the vulnerability can disrupt remote access and interrupt network services that depend on the affected firewall, increasing operational risk for organizations that expose the SSL VPN service.
The following reports contain further technical details:[/subscribe_to_unlock_form]
CVE-2026-76418 with a CVSS score of 8.6 is a remote denial-of-service vulnerability in the Remote Access SSL VPN service of Cisco Secure Firewall Adaptive Security Appliance (ASA) and Threat Defense (FTD) software. The flaw is caused by logic errors in the SSL VPN processing path when secondary authentication is enabled on a tunnel group. An unauthenticated remote attacker can exploit it by sending a crafted request while connecting to the SSL remote access VPN, without needing a successful VPN login. The affected processing path is reachable when the webvpn keyword is enabled on at least one interface and secondary-authentication-server-group is configured on any tunnel group or on DefaultWEBVPNGroup. A successful exploit forces the firewall to reload, creating a persistent denial-of-service condition. Because these appliances commonly function as perimeter firewalls and VPN gateways for enterprise networks, the vulnerability can disrupt remote access and interrupt network services that depend on the affected firewall, increasing operational risk for organizations that expose the SSL VPN service.
The following reports contain further technical details:[emaillocker id="1283"]
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