CVE intelligenceCISA KEV

CVE-2026-20079

Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability

Published Mar 4, 2026Sources checked Oct 28, 2026

10.0CRITICALCVSS out of 10

What this means

Actively exploited

CISA lists CVE-2026-20079 in its Known Exploited Vulnerabilities catalog, which means exploitation has been observed. The entry applies to Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management.

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.

Public exploit: Cataloged public exploit.

Cisco Security Advisories: Exploitation reported by Cisco Security Advisories (2026-09-16)
In August 2026, the Cisco PSIRT became aware of active exploitation of this vulnerability.
Rapid7 Metasploit: Cisco Secure Firewall Management Center Authentication Bypass RCE (2026-09-23 21:40:29.350562+00)
Rapid7 catalogs an exploit module for this CVE. Module availability does not establish exploitation in the wild or applicability to your environment.

What to do next

Remediation and response

Review the linked vendor advisory and apply the mitigation or fixed release for your affected product.

Cisco Security Advisories guidance

Vendor revision: Sep 16, 2026

Cisco has released software updates that address this vulnerability.

CISA KEVListedObserved exploitation

EPSS88.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors2Source-linked actor relationships

Overview

What is CVE-2026-20079?

A vulnerability in the web interface of Cisco Secure Firewall Management Center (FMC) Software 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.

This vulnerability is due to an improper system process that is created at boot time. An attacker could exploit this vulnerability by sending crafted HTTP requests to an affected device.

A successful exploit could allow the attacker to execute a variety of scripts and commands that allow root access to the device.

Source: NVD

Reported activity: In August 2026, the Cisco PSIRT became aware of active exploitation of this vulnerability.
Cisco Security Advisories · Published Sep 16, 2026

CISA says: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.CISA catalog due date Sep 12, 2026