Vulnerability in Cisco Secure Firewall Management Center (Fmc)

CVE-2026-20018

A vulnerability in the sftunnel functionality of Cisco Secure Firewall Management Center (FMC) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with administrative privileges to write arbitrary files as root on the underlying operating system. This vulnerability is due to insufficient validation of the directory path during file synchronization. An attacker could exploit this vulnerability by crafting a directory path outside of the expected file location. A successful exploit could allow the attacker to create or replace any file on the underlying operating system.

EPSS: 0.004 (35.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.9 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-20018?
CVE-2026-20018 is a medium-severity vulnerability in Cisco Secure Firewall Management Center (Fmc), classified under CWE-27. CVSS score: 5.9/10. Published 2026-03-04.
How severe is CVE-2026-20018?
Medium severity. CVSS v3 base score is 5.9 out of 10.