CVEs / CVE-2026-20079
CVE-2026-20079: Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
- Known exploited in the CISA KEV catalog since 9 Sep 2026
- critical 10 CVSS 3.1 (from the CNA)
- EPSS 88.6% chance of exploitation in the next 30 days, higher than 99% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.0 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.0.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.1.0 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.1.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.1.0.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.2 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.0 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.2.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.3 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.1.0.2 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.0.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.4 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.5 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.3.0 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.2 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.3.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.3 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.1.0.3 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.3.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.4 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.6 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.4.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.5 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.3.1.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.4.0 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.0.6.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.2.5.1 | — |
| Cisco Cisco Secure Firewall Management Center (FMC) | 7.4.1 | — |
Exploitation
| In CISA KEV since | 9 Sep 2026 |
|---|---|
| Due date for US federal agencies | 12 Sep 2026 |
| Used in ransomware campaigns | 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. |
Severity
| CVSS 3.1 | 10 criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:HScored by the CNA ([email protected]) |
|---|---|
| Weakness | CWE-288 |
References
- CVE-2026-20079 on NVD
- CVE-2026-20079 in the CISA KEV catalog
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-onprem-fmc-authbypass-5JPp45V2 (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk (cited by CISA)
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk (cited by CISA)
- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-onprem-fmc-authbypass-5JPp45V2 Vendor Advisory
- http://seclists.org/fulldisclosure/2026/Aug/80 Exploit, Mailing List, Third Party Advisory
- https://blog.talosintelligence.com/fmc-ongoing-exploitation/ Exploit, Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-20079 US Government Resource
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.