Auth bypass in Cisco Secure Firewall Management Center (Fmc)
CVE-2026-76420
A vulnerability in the internal configuration of the Apache JServ Protocol (AJP) connector for Cisco Secure FMC Software could allow an unauthenticated, remote attacker to impersonate a peer device. This vulnerability is due to incorrect initialization of encryption parameters for the AJP connector at boot time. An attacker could exploit this vulnerability by sending crafted packets to the AJP connector. A successful exploit could allow the attacker to execute commands as root and gain full control over the FMC REST APIs on the affected device. Note: This vulnerability can be exploited only if the valid sftunnel connection between Cisco Secure FMC Software and Cisco Secure FTD Software is down.
CVSS v3 metric
CVSS v3 base score 9.0 (Critical). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H.
Affected products
- Cisco Secure Firewall Management Center (Fmc) — versions 10.0.0, 10.0.1, 7.0.0
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-76420?
- CVE-2026-76420 is a critical-severity vulnerability in Cisco Secure Firewall Management Center (Fmc), classified under Improper Authorization. CVSS score: 9.0/10. Published 2026-09-16.
- How severe is CVE-2026-76420?
- Critical severity. CVSS v3 base score is 9.0 out of 10.