CVE-2026-20079Cisco Secure Firewall Management Center Authentication Bypass Remote Code Execution Vulnerability
- 10.0CriticalCVSS base score
- 88.7%Exploitation in 30 daysEPSS · top 0.2% of all CVEs
- YesKnown exploitedin CISA's KEV since 9 Sept 2026
- 2Public exploitsMetasploit, Nuclei and Exploit-DB
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.
Exploited in the wild
CISA lists this vulnerability in its Known Exploited Vulnerabilities catalog as Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability.
- Added
- 9 Sept 2026
- Fix due (US federal)
- 12 Sept 2026
- Used by ransomware
- Not known
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.
ENISA's EU Vulnerability Database lists it as exploited, from CISA's KEV and ENISA's EU KEV, since 9 Sept 2026.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Metasploit module and a Nuclei template for it. CISA's SSVC rates its exploitation: it is being exploited.
Show the exploits2
Metasploit modules1 module
- Cisco Secure Firewall Management Center Authentication Bypass RCE (Metasploit module) (opens in a new tab)
exploit/linux/http/cisco_fmc_auth_bypass_rceRank normaldisclosed 4 Mar 2026
Nuclei templates1 template
- Cisco Secure Firewall Management Center - Authentication Bypass (Nuclei template) (opens in a new tab)
http/cves/2026/CVE-2026-20079.yamlSeverity critical
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By cisco
- 5 months later
· 5 months later
Published
- 6 months later
· 6 months later
Added to CISA KEV
Known exploited in the wild
- 7 days later
· 7 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Analyzed | 3.1 | Critical10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 88.7% · top 0.2% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: active · Automatable: yes · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 10.0.
Affected products
Cisco · Cisco Secure Firewall Management Center (FMC)
- affected 7.0.0
- affected 7.0.0.1
- affected 7.0.1
- affected 7.1.0
- affected 7.0.1.1
- affected 7.1.0.1
- affected 7.0.2
- affected 7.2.0
- affected 7.0.2.1
- affected 7.0.3
- affected 7.1.0.2
- affected 7.2.0.1
- affected 7.0.4
- affected 7.2.1
- affected 7.0.5
- affected 7.3.0
- affected 7.2.2
- affected 7.3.1
- affected 7.2.3
- affected 7.1.0.3
- affected 7.2.3.1
- affected 7.2.4
- affected 7.0.6
- affected 7.2.4.1
- affected 7.2.5
- affected 7.3.1.1
- affected 7.4.0
- affected 7.0.6.1
- affected 7.2.5.1
- affected 7.4.1
- affected 7.2.6
- affected 7.4.1.1
- affected 7.0.6.2
- affected 7.2.7
- affected 7.2.5.2
- affected 7.3.1.2
- affected 7.2.8
- affected 7.6.0
- affected 7.4.2
- affected 7.2.8.1
- and 32 more
What to do
Exploitation: In August 2026, the Cisco PSIRT became aware of active exploitation of this vulnerability. Cisco strongly recommends that customers upgrade to a fixed software release to remediate this vulnerability.
References
References4
- cisco-sa-onprem-fmc-authbypass-5JPp45V2 (opens in a new tab)
- https://blog.talosintelligence.com/fmc-ongoing-exploitation/ (opens in a new tab)third-party-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20079 (opens in a new tab)government-resource
- http://seclists.org/fulldisclosure/2026/Aug/80 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- CISA KEV catalog (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-9438 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-20079)Record last updated .