9.9

CVE-2026-20324: cisco cisco secure firewall management center (fmc) Missing Authorization

CVSS: 9.9v3.1CriticalAwaiting analysis
Published 16-09-2026Last modified 18-09-2026
Open JSON

Vulnerability summary

CVE-2026-20324 is a critical (CVSS 9.9) Missing Authorization vulnerability in cisco cisco secure firewall management center (fmc). EPSS estimates a 0.45% chance of exploitation in the next 30 days, higher than 38% of scored vulnerabilities.

Overall risk
70/100
0100
High · default modelHow is this calculated?
CVSS score
9.9/10
010
Critical · v3.1 (CVE.org)
EPSS score
0.45%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 16-09-2026
    PublishedVulnerability first disclosed.
  2. 18-09-2026
    Last modifiedVulnerability information updated.

Description

A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure Firewall Management Center (FMC) Software could allow an authenticated, remote attacker to execute arbitrary commands as root. This vulnerability exists because a registered sftunnel peer has incorrect permissions to write an arbitrary file to any location on the device. An attacker could exploit this vulnerability by hijacking the sftunnel communication connection or being a valid registered sftunnel peer and sending an sftunnel command to write a malicious file to the disk of an affected device. A successful exploit could allow the attacker to write a file to the device that is executed with root privileges. To exploit this vulnerability, the attacker must have valid user credentials on the affected device.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.45%

Chance of exploitation in the next 30 days

Percentile

38%

Versus all other CVEs

30-day change

+0.01 pp

From 0.44% on 21-09-2026

21-09-202621-10-2026
EPSS score
0.45%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco1 product
  • cisco secure firewall management center (fmc)7.0.0 | 7.0.0.1 | 7.0.1 | 7.0.1.1 | 7.0.2 | 7.2.0 | 7.0.2.1 | 7.0.3 | 7.2.0.1 | 7.0.4 | 7.2.1 | 7.0.5 | 7.3.0 | 7.2.2 | 7.3.1 | 7.2.3 | 7.2.3.1 | 7.2.4 | 7.0.6 | 7.2.4.1 | 7.2.5 | 7.3.1.1 | 7.4.0 | 7.0.6.1 | 7.2.5.1 | 7.4.1 | 7.2.6 | 7.4.1.1 | 7.0.6.2 | 7.2.7 | 7.2.5.2 | 7.3.1.2 | 7.2.8 | 7.6.0 | 7.4.2 | 7.2.8.1 | 7.0.6.3 | 7.4.2.1 | 7.2.9 | 7.0.7 | 7.7.0 | 7.4.2.2 | 7.2.10 | 7.6.1 | 7.4.2.3 | 7.0.8 | 7.6.2 | 7.7.10 | 7.2.10.1 | 7.0.8.1 | 7.6.2.1 | 7.2.10.2 | 7.7.10.1 | 7.4.2.4 | 7.4.3 | 7.6.3 | 7.7.11 | 7.6.4 | 10.0.0 | 7.4.4 | 7.4.5 | 7.0.9 | 7.2.11 | 7.7.12 | 7.6.5 | 7.4.6 | 10.0.1 | 7.4.7

1 vendor · 1 product

References

1 links