Cisco Secure Firewall Zero-Day Vulnerability Actively Exploited

CISA has added a newly disclosed zero-day vulnerability (CVE-2026-20316) in Cisco Secure Firewall Management Center (FMC) Software to its Known Exploited Vulnerabilities catalog, confirming active exploitation. This flaw allows unauthenticated remote attackers to log in with a low-privilege account and access sensitive data. Cisco has rated the vulnerability as High severity, noting its potential for chaining with other flaws to escalate privileges, posing a significant risk to network security.