CVE-2026-20295

Cisco Secure Firewall Management Center and Secure Firewall Threat Defense Software sftunnel Memory Exhaustion Denial of Service Vulnerability

Severity
High 8.6
CVSS 3.1
Exploited
Not listed
EPSS
0.005
44.8th percentile
Discovered by
Third party
Vendor-published field
Published
Sep 16, 2026
Assigned by cisco

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.

Weakness: CWE-789

Affected products

Vendor Product Category Matched by
Cisco Cisco Secure Firewall Firewall / NGFW cna-assigner
Vendor-reported products (2)
  • Cisco · Cisco Secure Firewall Management Center (FMC)
  • Cisco · Cisco Secure Firewall Threat Defense (FTD) Software

Something wrong here?