Security Digest · Vulnerability record · Known exploited
CVE-2026-20079: Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
Exploited in the wild (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…
CISA KEV · added 2026-09-09 CVSS 10.0 Critical EPSS 88.5% · p99.8 Act now
Should you act?
Exploited: patch now if you run it
CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.
- Yes, if you run Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2026-09-09, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2026-09-12; treat that as the outer limit, not the target.
- EPSS 88.5%, percentile 99.8: FIRST’s model estimates a 88.5% chance of exploitation activity in the next 30 days, higher than 99.8% of all scored CVEs (very high). EPSS is a probability, not a verdict.
- Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.
- Editorial verdict: Act now. Cisco FMC CVE-2026-20079: Exploited Pre-Auth Root Bypass — If you run an on-prem Cisco Secure FMC that is not on a September 2026 hardening release, upgrade now and check it for compromise; state and ransomware actors are using this bug to take root on the box that controls your firewalls.
What it is
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.
CISA’s 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.
Weakness type: CWE-288.
Product: Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management · Assigned by: cisco · Published: 2026-03-04
Affected and fixed versions
| Vendor | Product | Affected versions (per CVE record) |
|---|---|---|
| Cisco | Cisco Secure Firewall Management Center (FMC) | 7.0.0, 7.0.0.1, 7.0.1, 7.1.0, 7.0.1.1, 7.1.0.1, 7.0.2, 7.2.0, 7.0.2.1, 7.0.3, 7.1.0.2, 7.2.0.1 |
Severity scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| cisco | 3.1 | 10 Critical | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- Attack vector: network (remotely reachable)
- Attack complexity: low
- Privileges required: none (no login)
- User interaction: none
- Scope: changed (can affect other components)
CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.
Exploitation and urgency
- CISA KEV: added 2026-09-09; federal due date 2026-09-12. Known ransomware use: Unknown.
- CISA 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.
- CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
- FIRST EPSS (model of 2026-10-21): 88.47% probability of exploitation activity in the next 30 days; percentile 99.8.
Timeline
- — CVE record published by cisco
- — erroneo.us brief: Cisco FMC CVE-2026-20079: Exploited Pre-Auth Root Bypass
- — Added to CISA’s Known Exploited Vulnerabilities catalog
- — CISA remediation deadline for US federal agencies
- — CVE record last updated
Sources and references
Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.
Vendor and project advisories, patches
- Listed in CISA KEV notes (sec.cloudapps.cisco.com) sec.cloudapps.cisco.com
Vulnerability records
- CVE.org record CVE-2026-20079 cve.org
- NVD entry CVE-2026-20079 nvd.nist.gov
Government
- CISA Known Exploited Vulnerabilities catalog entry cisa.gov
- Listed in CISA KEV notes (cisa.gov) cisa.gov
- Listed in CISA KEV notes (cisa.gov) cisa.gov
Other references from the CVE record and advisory
- blog.talosintelligence.com blog.talosintelligence.com
- seclists.org seclists.org
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