Secure Firewall ASA and FTD

CVE-2025-20222: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Buffer Vulnerability

A vulnerability in the RADIUS proxy feature for the IPsec VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.

Published

ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityHIGHCVSS 3.1 8.6
EPSS0.64%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 Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 7.1See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 6.2See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 7.1See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 7.3See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.3See the advisory
Cisco Firepower Threat Defense Software 7.1See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.3See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.4See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 7.4See the advisory
Cisco Firepower Threat Defense Software 6.6See the advisory
Cisco Firepower Threat Defense Software 6.4See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.3See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.4See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory
Cisco Firepower Threat Defense Software 7.0See the advisory
Cisco Firepower Threat Defense Software 7.4See the advisory
Cisco Firepower Threat Defense Software 7.2See the advisory

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

What it is

A vulnerability in the RADIUS proxy feature for the IPsec VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.

This vulnerability is due to improper processing of IPv6 packets. An attacker could exploit this vulnerability by sending IPv6 packets over an IPsec VPN connection to an affected device. A successful exploit could allow the attacker to trigger a reload of the device, resulting in a DoS condition.

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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