Cisco Warns of Exploited Firewall Flaw That Lets Attackers Crash SSL VPN Devices

Cisco has released security updates for a vulnerability that allows remote attackers to disrupt affected firewalls without authenticating, creating an immediate availability risk for organisations that depend on the devices for remote connectivity.

Tracked as CVE-2026-76418, the flaw affects the Remote Access SSL VPN service in Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) software. The Hong Kong Computer Emergency Response Team Coordination Centre, HKCERT, issued a high-risk bulletin on October 29, confirming that the vulnerability is being exploited in the wild and recommending the vendor’s fixes. Successful exploitation can force a targeted device to reload, causing a denial-of-service condition.

The disclosure creates a fresh patching priority for network and…