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High 8.6Published Sep 16, 2026

CVE-2026-20249Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software IKEv2 Certificate Authentication Denial of Service Vulnerability

Updated under an hour ago ()

Does this affect you?

It affects Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

A vulnerability in the certification authentication feature of Internet Key Exchange version 2 (IKEv2) for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly. This vulnerability is due to a logic error during the certificate authentication phase of the IKEv2 connection setup. An attacker could exploit this vulnerability by attempting to establish an IKEv2 VPN connection with a crafted certificate. A successful exploit could allow the attacker to cause the IKEv2 process to crash, causing a denial of service (DoS) condition.

CVSS
8.6 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Weakness (CWE)
CWE-704
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
cisco
NVD analysis
Awaiting Analysis
Record last updated
Sep 18, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
Cisco Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
cisco:secure_firewall_adaptive_security_appliance_asa_software (from the name)
9.16.1; 9.16.1.28; 9.16.2; 9.16.2.3; 9.16.2.7; 9.16.2.11; 9.16.2.13; 9.16.2.14; and 121 more ranges
CNA record
Cisco Cisco Secure Firewall Threat Defense (FTD) Software
cisco:secure_firewall_threat_defense_ftd_software (from the name)
7.0.0; 7.0.0.1; 7.0.1; 7.0.1.1; 7.0.2; 7.2.0; 7.0.2.1; 7.0.3; and 52 more ranges
CNA record

References

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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