Cisco Secure Firewall Management Center Software Information Disclosure and Disk Denial of Service Vulnerability

published 2026-09-16 53 d ago modified 2026-09-18 52 d ago also EUVD-2026-81126

cvss: 7.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 51%
public exploits: 0; none known

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.

CISA SSVC

Exploitation: none
Automatable: yes
Technical impact: partial
Assessed: 52 d ago (2026-09-18)

Exploit prediction

0.66% chance of exploitation in the next 30 days, higher than 51% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected products

Cisco Cisco Secure Firewall Management Center (FMC)

Classification

Weakness

CWE-306 Missing Authentication for Critical Functionality

References

sec.cloudapps.cisco.com /security/center/content/CiscoSecurityAdvisory/cisco-sa-fmc-mulivulns-4PsnFwvx

Sources

CVE List CVE-2026-20343
NVD CVE-2026-20343

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Summary