Secure Firewall ASA and FTD

CVE-2026-20050: Cisco Secure Firewall Threat Defense Decryption Policy Denial of Service Vulnerability

A vulnerability in the Do Not Decrypt exclusion feature of the SSL decryption feature of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

Published

ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityMEDIUMCVSS 3.1 6.8
EPSS0.39%Chance of exploitation in 30 days
Public exploitNot tracked
FixNot yet

Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.

Affected and fixed versions

Product / branchFixed in
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.1See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.1See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.1See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.3See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.3See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.1See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.3See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.3See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.6See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.7See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.6See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.6See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.7See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.6See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.7See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.2See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.4See the advisory
Cisco Secure Firewall Threat Defense (FTD) Software 7.0See the advisory

Always confirm against the vendor advisory, which lists every fixed hotfix.

What it is

A vulnerability in the Do Not Decrypt exclusion feature of the SSL decryption feature of Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to improper memory management during the inspection of TLS 1.2 encrypted traffic. An attacker could exploit this vulnerability by sending crafted TLS 1.2 encrypted traffic through an affected device. A successful exploit could allow the attacker to cause a reload of an affected device. Note: This vulnerability only affects traffic that is encrypted by TLS 1.2. Other versions of TLS are not affected.

Exploitation

The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

Sources

KEV status, EPSS score and vendor data refreshed automatically, last on 11 Oct 2026.

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