CVE-2026-20249
published 2026-09-16CVE-2026-20249: A vulnerability in the certification authentication feature of Internet Key Exchange version 2 (IKEv2) for Cisco Secure Firewall Adaptive Security Appliance…
PriorityP352high8.6CVSS 3.1
AVNACLPRNUINSCCNINAH
EPSS
0.40%
33.0th percentile
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.
Affected
189 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
| cisco | cisco_secure_firewall_adaptive_security_appliance_software | — | — |
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GHSA
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 Firewa
ghsa_unreviewed·2026-09-16
CVE-2026-20249 [HIGH] CWE-704 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 Firewa
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.
VulDB
Cisco Adaptive Security Appliance Software Certification Authentication denial of service
vuldb·2026-09-16·CVSS 8.6
CVE-2026-20249 [HIGH] Cisco Adaptive Security Appliance Software Certification Authentication denial of service
A vulnerability was found in Cisco Adaptive Security Appliance Software and Threat Defense Software. It has been classified as critical. Affected by this issue is some unknown functionality of the component Certification Authentication. The manipulation leads to denial of service.
This vulnerability is uniquely identified as CVE-2026-20249. The attack is possible to be carried out remotely. No exploit exists.
Upgrading the affected component is recommended.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
2026-09-16
Published