Cisco confirms CVE-2026-20079 Secure FMC flaw exploited in attacks
Cisco confirmed active exploitation of CVE-2026-20079, a CVSS 10.0 authentication bypass enabling unauthenticated root command execution in Secure FMC; CISA added it to KEV.
Cisco confirmed in August 2026 that CVE-2026-20079 (CVSS 10.0), an unauthenticated authentication bypass in Secure Firewall Management Center, is being actively exploited, allowing remote attackers to execute scripts and commands as root via crafted HTTP requests to the web interface. CISA added the flaw to its Known Exploited Vulnerabilities catalog, ordering federal civilian agencies to patch by September 12, 2026. Shared IOCs, identical hot fixes, and a July 23 log entry suggest CVE-2026-20079 was used alongside the separately exploited static-credential flaw CVE-2026-20316 in the same attacks. Cisco released patches and cloud fixes, warns hot fixes do not remediate already-compromised devices, and says there are no workarounds.