🔐 CVE Alert

CVE-2026-20249

HIGH 8.6

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

CVSS Score
8.6
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-704
Vendor cisco
Product cisco secure firewall adaptive security appliance (asa) software
Ecosystems
Industries
NetworkingTelecommunications
Published Sep 16, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
High

Affected Versions

Cisco / Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
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 9.16.3.3 9.16.3 9.16.3.14 9.18.1 9.16.3.15 9.18.1.3 9.18.2 9.16.3.19 9.16.3.23 9.18.2.5 9.16.4 9.18.2.7 9.19.1 9.16.4.9 9.18.2.8 9.16.4.14 9.18.3 9.19.1.5 9.16.4.18 9.19.1.9 9.18.3.39 9.16.4.19 9.19.1.12 9.18.3.46 9.16.4.27 9.19.1.18 9.18.3.53 9.18.3.55 9.16.4.38 9.16.4.39 9.18.3.56 9.20.1 9.16.4.42 9.19.1.22 9.18.4 9.20.1.5 9.18.4.5 9.19.1.24 9.16.4.48 9.18.4.8 9.20.2 9.19.1.27 9.16.4.55 9.18.4.22 9.20.2.10 9.16.4.57 9.19.1.28 9.18.4.24 9.20.2.21 9.16.4.61 9.19.1.31 9.18.4.29 9.20.2.22 9.16.4.62 9.18.4.34 9.20.3 9.16.4.67 9.16.4.70 9.18.4.40 9.23.1 9.22.1.1 9.16.4.71 9.20.3.4 9.18.4.47 9.20.3.7 9.19.1.37 9.16.4.76 9.20.3.9 9.19.1.38 9.18.4.50 9.22.1.3 9.20.3.10 9.22.1.2 9.18.4.52 9.20.3.13 9.22.1.6 9.18.4.53 9.16.4.82 9.22.2 9.20.3.16 9.19.1.42 9.18.4.57 9.16.4.84 9.23.1.3 9.20.3.20 9.22.2.4 9.23.1.7 9.20.4 9.22.2.9 9.23.1.13 9.20.4.7 9.22.2.13 9.18.4.66 9.20.4.10 9.23.1.19 9.16.4.85 9.22.2.14 9.18.4.67 9.24.1 9.18.4.68 9.23.1.22 9.20.4.14 9.22.2.20 9.18.4.71 9.20.4.19 9.23.1.26 9.16.4.89 9.22.2.32 9.18.4.76 9.22.3 9.24.1.5 9.20.4.22 9.24.1.9 9.20.4.28 9.16.4.92 9.18.4.135 9.23.1.195 9.20.4.30 9.24.1.155 9.23.1.32 9.18.4.82
Cisco / Cisco Secure Firewall Threat Defense (FTD) Software
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 7.2.0.1 7.0.4 7.2.1 7.0.5 7.3.0 7.2.2 7.2.3 7.3.1 7.2.4 7.0.6 7.2.5 7.2.4.1 7.3.1.1 7.4.0 7.0.6.1 7.2.5.1 7.4.1 7.2.6 7.0.6.2 7.4.1.1 7.2.7 7.2.5.2 7.3.1.2 7.2.8 7.6.0 7.4.2 7.2.8.1 7.0.6.3 7.4.2.1 7.2.9 7.0.7 7.7.0 7.4.2.2 7.2.10 7.6.1 7.4.2.3 7.0.8 7.6.2 7.7.10 7.7.11 7.0.8.1 7.6.2.1 7.7.10.1 7.4.2.4 7.2.10.2 7.4.3 7.6.4 10.0.0 7.4.4 7.0.9 7.2.11 7.4.7

References

NVD ↗ CVE.org ↗ EPSS Data ↗
sec.cloudapps.cisco.com: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ikev2cert-dos-uWyc2xtv