Vulnerability Report

CVE-2026-20079

CISA KEV Active

Title: Authentication Bypass and RCE in Cisco Secure Firewall Management Center (FMC) Software

Auth Bypass

Proof Of Concept

PoC Available for CVE-2026-20079

CWE Category CWE-288

Published Date Mar 04, 2026

Modified Date Sep 10, 2026

Exploit Status Available

Score 10.0 CVSS v3.1

Exploit Probability (EPSS)

74.70%

Vulnerability Summary

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. 

Impacted Vendors

cisco 1

Reference Links

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-onprem-fmc-authbypass-5JPp45V2

CVSS v3.1

Source Entity [email protected]

Severity CRITICAL

10.0

Attack Vector

NETWORK

Complexity

LOW

Privileges

N/A

Interaction

NONE

Confidentiality

N/A

Integrity

N/A

Availability

N/A

Scope

CHANGED

RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-20079 Exploits & PoCs (Proof Of Concept)

GitHub https://github.com/b1gchoi/CVE-2026-20079

View Code

GitHub https://github.com/Sushilsin/CVE-2026-20079

View Code

September 10, 2026 MODIFIED