Exploited CVEs / Cisco / CVE-2026-20079

CVE-2026-20079

Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2026-09-12 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Cisco Security Advisories (PSIRT), linked below.

Risk summary

In the top 10 of the Senserva CVE Ranking (as of 2026-09-15)

CriticalCISA KEV

10.0

CVSS v3 base

76%

EPSS exploit probability

Critical

Severity

2026-09-09

Added to KEV

2026-09-12 (past due)

CISA due date

Actively exploited Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management vulnerability, Critical severity, CVSS v3 10.0. Added to the CISA KEV catalog 2026-09-09.

CISA required action Official fix for CVE-2026-20079 What the press says Admin questions #1 hottest CVE right now

Senserva AI Opinion and rich prompt for CVE-2026-20079

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2026-20079, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2026-20079.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (morning and afternoon US Central)):
- CVE-2026-20079: Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability
- Affected: Cisco Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management
- Severity: Critical, CVSS v3 10.0; EPSS 30-day exploitation probability 76%
- Added to CISA KEV: 2026-09-09; federal remediation due 2026-09-12
- Ransomware-linked: no
- 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 dis...
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

The fix ships from the vendor: Cisco Security Advisories (PSIRT).

Do this now: Federal remediation deadline 2026-09-12; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated September 15, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2026-20079

Published: 2026-09-09
Last revised: 2026-09-09
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

CISA confirmed active exploitation of CVE-2026-20079 on 2026-09-09, and its EPSS exploit probability moved from 36% to 76% by 2026-09-11.

Drawn by Senserva Vivid from the Senserva change record. Hover any point for its date and value.

2026-09-09 added to the CISA KEV catalog by CISA
2026-09-10 CVSS 0.0 to 10.0; EPSS first scored at 35.9%
2026-09-11 EPSS 35.9% to 75.8%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2026-09-12 (past due).

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.

Official fix for CVE-2026-20079

The authoritative fix and affected-version list are published by the vendor. Find the Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management advisory on Cisco Security Advisories (PSIRT).

Cisco Security Advisories (PSIRT)CISA KEV entry

Common questions about CVE-2026-20079

Is CVE-2026-20079 actively exploited?

Yes. CVE-2026-20079 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2026-09-09, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 76%.

What is the CISA deadline and required action for CVE-2026-20079?

CISA set the federal (BOD 22-01) remediation due date at 2026-09-12, which has passed; treat any unremediated system as overdue. The verbatim 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.

What fixes CVE-2026-20079?

The authoritative fix is in the vendor advisory: see Cisco Security Advisories (PSIRT) for the patched Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2026-20079?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-20079's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (morning and afternoon US Central).

Scope and sources

More exploited Cisco CVEs: CVE-2026-76461 CVE-2026-20349 CVE-2026-20316 CVE-2008-4128 CVE-2026-20230 CVE-2026-20262 CVE-2026-20245 CVE-2026-20182
All Cisco exploited CVEs on one page: Cisco vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.