CVE-2026-20079
Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management
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.
Ransomware groups exploiting CVE-2026-20079
Qilin ransomware was first observed in July of 2022. Qilin Ransomware is written in Golang and supports multiple encryption modes; all of which are controlled by the operator. Qilin actors practice double extortion – demanding payment for a decryptor, as well
Exploitation is attributed to these groups across their recorded activity. It does not follow that every organisation they listed was reached through CVE-2026-20079 — the source data does not record an entry point per incident.
Exploitation status
CISA Known Exploited Vulnerabilities
Listed by CISA on 9 September 2026. US federal agencies were required to remediate it by 12 September 2026.
EPSS — exploitation probability
FIRST puts the probability of exploitation activity in the next 30 days at 88.7%, which is higher than 99.8% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Recent listings by these groups
Disclosures from the groups above, newest first.
Frequently asked questions
Is CVE-2026-20079 being exploited by ransomware groups?
Yes. CVE-2026-20079 is recorded as exploited by Qilin. Between them these groups account for 2,550 victim disclosures in this database.
What does CVE-2026-20079 affect?
CVE-2026-20079 affects Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management. 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.
How severe is CVE-2026-20079?
CVE-2026-20079 is rated CRITICAL with a CVSS base score of 10. EPSS puts the probability of exploitation in the next 30 days at 88.7%, higher than 99.8% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 12 September 2026.
How should organisations respond to CVE-2026-20079?
Apply the vendor patch for Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.