Cisco FMC: Auth Bypass & Remote Code Execution via Web Interface
CVE-2026-20079 Published on March 4, 2026

Cisco Secure Firewall Management Center Authentication Bypass Remote Code Execution Vulnerability
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. 

NVD

Known Exploited Vulnerability

This Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerabil vulnerability is part of CISA's list of Known Exploited Vulnerabilities. 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.

The following remediation steps are recommended / required by September 12, 2026: 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 applicab

Vulnerability Analysis

CVE-2026-20079 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is considered to have a low attack complexity. This vulnerability is known to be actively exploited by threat actors in an automatable fashion. The potential impact of an exploit of this vulnerability is considered to be critical as this vulnerability has a high impact to the confidentiality, integrity and availability of this component.

Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
CHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH

Weakness Type

Authentication Bypass Using an Alternate Path or Channel

A product requires authentication, but the product has an alternate path or channel that does not require authentication.


Products Associated with CVE-2026-20079

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Cisco Secure Firewall Management Center
 

Affected Versions

Cisco Secure Firewall Management Center (FMC):

Exploit Probability

EPSS
38.70%
Percentile
98.43%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.