Cisco Patches Zero-Day Vulnerability (CVE-2026-20349) Exploited for DoS Attacks on Firewalls

Cisco has released a patch for a critical zero-day vulnerability, identified as CVE-2026-20349, which was being actively exploited to launch Denial-of-Service (DoS) attacks against its Secure Firewall ASA and FTD devices. The flaw could be exploited remotely without authentication.