CVE-2026-20079
Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
IN CISA KEV
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.
- Vendor
- Cisco
- Product
- Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management
- CVSS 3.1
- 10 (critical), scored by psirt@cisco.comCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- CWE
- CWE-288
- Published
- 2026-03-04
- NVD modified
- 2026-09-16
- NVD status
- Analyzed
CISA KEV
- Date added
- 2026-09-09
- Due date
- 2026-09-12
- Ransomware use
- Unknown
- Required action
- 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.
EPSS
88.2% chance of exploitation in the next 30 days (percentile 99th)
FIRST EPSS, updated 17 Oct 2026. About EPSS
CVSS is severity, EPSS is likelihood, KEV means already exploited. EPSS is a statistical probability, not a certainty: a low score does not make a bug safe, and a high one does not prove it is being exploited.
References
- sec.cloudapps.cisco.com (Vendor Advisory)
- www.cisa.gov (US Government Resource)
Data last updated 18 Oct 2026. Sources: NVD API 2.0, CISA KEV catalog, FIRST EPSS. Links: NVD, CISA KEV. Metadata only. ThreatWire does not host exploit code.