CISCO: 🔗 Cisco Security Advisory: Cisco Secure Firewall Management Center Software Authentication Bypass Vulnerability

CISCO Security Advisory

Published Date: Not specified

CVE: CVE-2026-20079

Advisory Summary

🗓️ Calendar • Aug 5, 2026

🚨 ⚠️ Cisco Secure Firewall FMC Auth Bypass (CVE-2026-20079) — Critical Risk
A Critical vulnerability has been disclosed in the Cisco Secure Firewall Management Center (FMC) web interface. It could allow an unauthenticated, remote attacker to bypass authentication and execute scripts on the device, ultimately enabling root access to the underlying operating system.

• Attackers can exploit the FMC web interface to reach an unauthorized execution path.
• Successful exploitation allows attackers to run scripts/commands with root-level privileges.
• This materially increases the likelihood of full device compromise, persistence, and downstream control over managed security policies.

• The issue stems from an improper system process created at boot time, which can be leveraged through crafted HTTP requests.

• Cisco notes that if the FMC management interface is not publicly reachable, the effective attack surface is reduced.
• However, any reachable management endpoint (including via misconfigured VPN, external DNS, or exposed reverse proxies) increases risk.

• ✅ Cisco has released software updates to address this vulnerability.
• ❌ There are no workarounds.

• Restrict inbound access (ACLs/security groups), remove public routing where possible.
• Monitor for anomalous crafted HTTP request patterns targeting the FMC management UI.

• Watch for unusual unauthenticated HTTP traffic to the FMC management interface.
• Look for post-exploitation signs consistent with script/command execution leading to privileged actions.

• CVE-2026-20079

-2026-20079

Reference: Vendor Advisory