Cisco Fixes High-Severity Firewall Vulnerability (CVE-2026-20349) Actively Exploited for Denial of Service

Cisco has released hot fixes for a high-severity vulnerability (CVE-2026-20349) in its Secure Firewall Adaptive Security Appliance (ASA) and Firewall Threat Defense (FTD) software. Attackers are actively exploiting this flaw via specially crafted HTTP requests to cause unexpected reloads and denial-of-service conditions. The vulnerability affects Remote Access SSL VPN services and has been added to CISA's Known Exploited Vulnerabilities catalog.