CVE-2026-20295

high

Description

A vulnerability in the sftunnel inter-device communication protocol of Cisco Secure FMC Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to exhaust the available memory of an affected device. This vulnerability is due to improper management of memory resources during sftunnel TLS connection setup. An attacker could exploit this vulnerability by sending crafted sftunnel TLS frames to an affected device during the connection setup. A successful exploit could allow the attacker to exhaust the available memory on the affected device, which could result in a DoS condition.

References

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-fmcftd-sftun-multivulns-WGVHOrN3

Details

Source: Mitre, NVD

Published: 2026-09-16

Updated: 2026-09-17

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 8.6

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Severity: High

EPSS

EPSS: 0.00549