CVE-2026-20343

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

Published Sep 16, 2026 CVSS 3.1 · 7.5 High EPSS < 1% KEV · Not listed
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.&nbsp;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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Cisco
Cisco secure Firewall Management Center
Vendors & Products Cisco
Cisco secure Firewall Management Center
Type Values Removed Values Added
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.&nbsp;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.
Title Cisco Secure Firewall Management Center Software Information Disclosure and Disk Denial of Service Vulnerability
Weaknesses CWE-306
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
cisco
Published
Updated
Sep 18, 2026, 2:46 PM
Reserved
Oct 8, 2025, 11:59 AM
Status
Awaiting Analysis
Published
Sep 16, 2026, 9:17 PM
Modified
Sep 18, 2026, 3:17 PM