Auth bypass in Cisco Secure Firewall Management Center (Fmc)
CVE-2026-20343
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.
Vulnerability class: Broken Authentication
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Cisco Secure Firewall Management Center (Fmc) — versions 10.0.0, 10.0.1, 7.3.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-20343?
- CVE-2026-20343 is a high-severity vulnerability in Cisco Secure Firewall Management Center (Fmc), classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2026-09-16.
- How severe is CVE-2026-20343?
- High severity. CVSS v3 base score is 7.5 out of 10.