Exploited vulnerability · CISA KEV

Is CVE-2026-20079 exploited? Yes: in CISA KEV since 9 Sep 2026

Gociux · Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management · data: CISA KEV, CVE record, FIRST EPSS

Yes. CVE-2026-20079, Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability, is being exploited in the wild. CISA added it to its Known Exploited Vulnerabilities catalog on 9 Sep 2026, 189 days after it was published. It affects Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management, an internet-facing product of the kind attackers use for initial access. If you run it, CISA's required action is: 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.

What it is

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.

What to do

1. Check whether you run it. Look for Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management in your asset inventory, including appliances and cloud images. Stack check lists every exploited Cisco CVE at once.
2. Apply the fix. 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.
3. If you can't patch today, take the affected service off the internet or restrict who can reach it, and check its logs for signs of compromise since 4 Mar 2026.
4. Get told next time. Email alerts when CISA adds a CVE for Cisco.

References

• sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-onpr
• nvd.nist.gov/vuln/detail/CVE-2026-20079

Sources: CISA KEV (exploitation, ransomware use, required action, due date), the CVE record (publication date, CVSS, CNA), NVD and FIRST EPSS (live score). More: all KEV additions in September 2026 · Cisco scorecard · act-now radar.