CVE-2026-20079: Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability

Required action (CISA's text)

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

Description (NVD)

Cisco Secure Firewall Management Center (FMC) Software and Cisco Security Cloud Control (SCC) Firewall Management contain an authentication Bypass using an alternate path or channel vulnerability that could allow an unauthenticated, remote attacker to bypass authentication and execute script files on an affected device to obtain root access to the underlying operating system.

Vendor advisories

• Kwetsbaarheden verholpen in Cisco Secure Firewall ASA, Threat Defense en Management Center

SOURCES

• CISA KEVCISA Known Exploited Vulnerabilities catalog
• NCSC-NLadvisories.ncsc.nl/advisory

Other Cisco flaws

• CVE-2026-20320: Cisco BroadWorks Improper Restriction of XML External Entity Reference Vulnerability
• CVE-2026-76418: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
• CVE-2026-76519: Cisco Secure Email Gateway Relative Path Traversal Vulnerability
• CVE-2026-76504: Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
• CVE-2026-76460: Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability

Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.