CVE-2026-20079 KEV
10.0
CRITICAL · CVSS 3.1 · EPSS 88.2% (pctl 100)
Patch first
On CISA KEV — known exploited in the wild, due 2026-09-12.
Description
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.
Scoring
| CVSS | 10.0 (CRITICAL, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| EPSS | 88.18% — more likely to be exploited than 100% of all CVEs |
| Weakness | CWE-288 |
| On CISA KEV | yes — remediate by 2026-09-12 |
| Public exploit | none known |
| Published | 2026-03-04 |
| Last modified | 2026-09-16 |
CISA KEV
| Name | Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability |
|---|---|
| Added | 2026-09-09 |
| Due | 2026-09-12 |
| Vendor / product | Cisco / Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management |
| Ransomware use | none reported |
Affected (1)
| Vendor | Product |
|---|---|
| cisco | secure firewall management center |
References
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-onprem-fmc-authbypass-5JPp45V2
- http://seclists.org/fulldisclosure/2026/Aug/80
- https://blog.talosintelligence.com/fmc-ongoing-exploitation/
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20079
→ the Explorer · watch your stack · NVD