Answer in brief
CVE-2026-20249 records a Unknown severity vulnerability in Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software IKEv2 Certificate Authentication Denial of Service Vulnerability. The current sources do not mark it as known exploited. The current feed maps Cisco/Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (generic), Cisco/Cisco Secure Firewall Threat Defense (FTD) Software (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Cisco/Cisco Secure Firewall Adaptive Security Appliance (ASA) Software (generic), Cisco/Cisco Secure Firewall Threat Defense (FTD) Software (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Cisco/Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwaregeneric | 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 | Not reported |
| Cisco/Cisco Secure Firewall Threat Defense (FTD) Softwaregeneric | 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 | Not reported |
Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 16, 2026
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.
Quoted source text, attributed separately from HOL analysis.