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UK Cyber Defence
VulnerabilityAwaiting Analysis

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…

MEDIUM 5.9EPSS 0.45%

Does this matter?

Lower severity and a low EPSS score (0.45%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1
5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:H
EPSS
0.45% probability · 39th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-27
Source
psirt@cisco.com
EPSS trend
0%3%5%26 October 2026: 0.45%26 October 202626 October 2026

EPSS 0.4% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.