7.5

CVE-2026-20343: cisco cisco secure firewall management center (fmc)

CVSS: 7.5v3.1HighAwaiting analysis
Published 16-09-2026Last modified 18-09-2026
Open JSON

Vulnerability summary

CVE-2026-20343 is a high (CVSS 7.5) 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
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (CVE.org)
EPSS score
0.45%
0%100%
Low · 0.00 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 a critical API for Cisco Secure FMC Software could allow an unauthenticated, remote attacker to download sensitive files and use unbounded disk space. This vulnerability exists because a critical API lacks authentication. An attacker could exploit this vulnerability by repeatedly invoking the API. A successful exploit could allow the attacker to download sensitive files that should be restricted and consume disk space so the device could become unresponsive, causing a DoS condition.

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

0.00 pp

From 0.45% 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)7.3.0 | 7.3.1 | 7.3.1.1 | 7.4.0 | 7.4.1 | 7.4.1.1 | 7.3.1.2 | 7.6.0 | 7.4.2 | 7.4.2.1 | 7.7.0 | 7.4.2.2 | 7.6.1 | 7.4.2.3 | 7.6.2 | 7.7.10 | 7.6.2.1 | 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 | 7.7.12 | 7.6.5 | 7.4.6 | 10.0.1 | 7.4.7

1 vendor · 1 product

References

1 links