HIGH
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software IKEv2 Certificate Authentication Denial of Service Vulnerability
Published Sep 16, 2026
8.6
HIGHCVSS 3.1
EPSS 0.40%
Description
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 products
-
- Version 9.16.1StatusaffectedConstraints-
- Version 9.16.1.28StatusaffectedConstraints-
- Version 9.16.2StatusaffectedConstraints-
- Version 9.16.2.11StatusaffectedConstraints-
- Version 9.16.2.13StatusaffectedConstraints-
- Version 9.16.2.14StatusaffectedConstraints-
- Version 9.16.2.3StatusaffectedConstraints-
- Version 9.16.2.7StatusaffectedConstraints-
- Version 9.16.3StatusaffectedConstraints-
- Version 9.16.3.14StatusaffectedConstraints-
- Version 9.16.3.15StatusaffectedConstraints-
- Version 9.16.3.19StatusaffectedConstraints-
- Version 9.16.3.23StatusaffectedConstraints-
- Version 9.16.3.3StatusaffectedConstraints-
- Version 9.16.4StatusaffectedConstraints-
- Version 9.16.4.14StatusaffectedConstraints-
- Version 9.16.4.18StatusaffectedConstraints-
- Version 9.16.4.19StatusaffectedConstraints-
- Version 9.16.4.27StatusaffectedConstraints-
- Version 9.16.4.38StatusaffectedConstraints-
- Version 9.16.4.39StatusaffectedConstraints-
- Version 9.16.4.42StatusaffectedConstraints-
- Version 9.16.4.48StatusaffectedConstraints-
- Version 9.16.4.55StatusaffectedConstraints-
- Version 9.16.4.57StatusaffectedConstraints-
- Version 9.16.4.61StatusaffectedConstraints-
- Version 9.16.4.62StatusaffectedConstraints-
- Version 9.16.4.67StatusaffectedConstraints-
- Version 9.16.4.70StatusaffectedConstraints-
- Version 9.16.4.71StatusaffectedConstraints-
- Version 9.16.4.76StatusaffectedConstraints-
- Version 9.16.4.82StatusaffectedConstraints-
- Version 9.16.4.84StatusaffectedConstraints-
- Version 9.16.4.85StatusaffectedConstraints-
- Version 9.16.4.89StatusaffectedConstraints-
- Version 9.16.4.9StatusaffectedConstraints-
- Version 9.16.4.92StatusaffectedConstraints-
- Version 9.18.1StatusaffectedConstraints-
- Version 9.18.1.3StatusaffectedConstraints-
- Version 9.18.2StatusaffectedConstraints-
- Version 9.18.2.5StatusaffectedConstraints-
- Version 9.18.2.7StatusaffectedConstraints-
- Version 9.18.2.8StatusaffectedConstraints-
- Version 9.18.3StatusaffectedConstraints-
- Version 9.18.3.39StatusaffectedConstraints-
- Version 9.18.3.46StatusaffectedConstraints-
- Version 9.18.3.53StatusaffectedConstraints-
- Version 9.18.3.55StatusaffectedConstraints-
- Version 9.18.3.56StatusaffectedConstraints-
- Version 9.18.4StatusaffectedConstraints-
- Version 9.18.4.135StatusaffectedConstraints-
- Version 9.18.4.22StatusaffectedConstraints-
- Version 9.18.4.24StatusaffectedConstraints-
- Version 9.18.4.29StatusaffectedConstraints-
- Version 9.18.4.34StatusaffectedConstraints-
- Version 9.18.4.40StatusaffectedConstraints-
- Version 9.18.4.47StatusaffectedConstraints-
- Version 9.18.4.5StatusaffectedConstraints-
- Version 9.18.4.50StatusaffectedConstraints-
- Version 9.18.4.52StatusaffectedConstraints-
- Version 9.18.4.53StatusaffectedConstraints-
- Version 9.18.4.57StatusaffectedConstraints-
- Version 9.18.4.66StatusaffectedConstraints-
- Version 9.18.4.67StatusaffectedConstraints-
- Version 9.18.4.68StatusaffectedConstraints-
- Version 9.18.4.71StatusaffectedConstraints-
- Version 9.18.4.76StatusaffectedConstraints-
- Version 9.18.4.8StatusaffectedConstraints-
- Version 9.18.4.82StatusaffectedConstraints-
- Version 9.19.1StatusaffectedConstraints-
- Version 9.19.1.12StatusaffectedConstraints-
- Version 9.19.1.18StatusaffectedConstraints-
- Version 9.19.1.22StatusaffectedConstraints-
- Version 9.19.1.24StatusaffectedConstraints-
- Version 9.19.1.27StatusaffectedConstraints-
- Version 9.19.1.28StatusaffectedConstraints-
- Version 9.19.1.31StatusaffectedConstraints-
- Version 9.19.1.37StatusaffectedConstraints-
- Version 9.19.1.38StatusaffectedConstraints-
- Version 9.19.1.42StatusaffectedConstraints-
- Version 9.19.1.5StatusaffectedConstraints-
- Version 9.19.1.9StatusaffectedConstraints-
- Version 9.20.1StatusaffectedConstraints-
- Version 9.20.1.5StatusaffectedConstraints-
- Version 9.20.2StatusaffectedConstraints-
- Version 9.20.2.10StatusaffectedConstraints-
- Version 9.20.2.21StatusaffectedConstraints-
- Version 9.20.2.22StatusaffectedConstraints-
- Version 9.20.3StatusaffectedConstraints-
- Version 9.20.3.10StatusaffectedConstraints-
- Version 9.20.3.13StatusaffectedConstraints-
- Version 9.20.3.16StatusaffectedConstraints-
- Version 9.20.3.20StatusaffectedConstraints-
- Version 9.20.3.4StatusaffectedConstraints-
- Version 9.20.3.7StatusaffectedConstraints-
- Version 9.20.3.9StatusaffectedConstraints-
- Version 9.20.4StatusaffectedConstraints-
- Version 9.20.4.10StatusaffectedConstraints-
- Version 9.20.4.14StatusaffectedConstraints-
- Version 9.20.4.19StatusaffectedConstraints-
- Version 9.20.4.22StatusaffectedConstraints-
- Version 9.20.4.28StatusaffectedConstraints-
- Version 9.20.4.30StatusaffectedConstraints-
- Version 9.20.4.7StatusaffectedConstraints-
- Version 9.22.1.1StatusaffectedConstraints-
- Version 9.22.1.2StatusaffectedConstraints-
- Version 9.22.1.3StatusaffectedConstraints-
- Version 9.22.1.6StatusaffectedConstraints-
- Version 9.22.2StatusaffectedConstraints-
- Version 9.22.2.13StatusaffectedConstraints-
- Version 9.22.2.14StatusaffectedConstraints-
- Version 9.22.2.20StatusaffectedConstraints-
- Version 9.22.2.32StatusaffectedConstraints-
- Version 9.22.2.4StatusaffectedConstraints-
- Version 9.22.2.9StatusaffectedConstraints-
- Version 9.22.3StatusaffectedConstraints-
- Version 9.23.1StatusaffectedConstraints-
- Version 9.23.1.13StatusaffectedConstraints-
- Version 9.23.1.19StatusaffectedConstraints-
- Version 9.23.1.195StatusaffectedConstraints-
- Version 9.23.1.22StatusaffectedConstraints-
- Version 9.23.1.26StatusaffectedConstraints-
- Version 9.23.1.3StatusaffectedConstraints-
- Version 9.23.1.32StatusaffectedConstraints-
- Version 9.23.1.7StatusaffectedConstraints-
- Version 9.24.1StatusaffectedConstraints-
- Version 9.24.1.155StatusaffectedConstraints-
- Version 9.24.1.5StatusaffectedConstraints-
- Version 9.24.1.9StatusaffectedConstraints-
- Version
-
- Version 10.0.0StatusaffectedConstraints-
- Version 7.0.0StatusaffectedConstraints-
- Version 7.0.0.1StatusaffectedConstraints-
- Version 7.0.1StatusaffectedConstraints-
- Version 7.0.1.1StatusaffectedConstraints-
- Version 7.0.2StatusaffectedConstraints-
- Version 7.0.2.1StatusaffectedConstraints-
- Version 7.0.3StatusaffectedConstraints-
- Version 7.0.4StatusaffectedConstraints-
- Version 7.0.5StatusaffectedConstraints-
- Version 7.0.6StatusaffectedConstraints-
- Version 7.0.6.1StatusaffectedConstraints-
- Version 7.0.6.2StatusaffectedConstraints-
- Version 7.0.6.3StatusaffectedConstraints-
- Version 7.0.7StatusaffectedConstraints-
- Version 7.0.8StatusaffectedConstraints-
- Version 7.0.8.1StatusaffectedConstraints-
- Version 7.0.9StatusaffectedConstraints-
- Version 7.2.0StatusaffectedConstraints-
- Version 7.2.0.1StatusaffectedConstraints-
- Version 7.2.1StatusaffectedConstraints-
- Version 7.2.10StatusaffectedConstraints-
- Version 7.2.10.2StatusaffectedConstraints-
- Version 7.2.11StatusaffectedConstraints-
- Version 7.2.2StatusaffectedConstraints-
- Version 7.2.3StatusaffectedConstraints-
- Version 7.2.4StatusaffectedConstraints-
- Version 7.2.4.1StatusaffectedConstraints-
- Version 7.2.5StatusaffectedConstraints-
- Version 7.2.5.1StatusaffectedConstraints-
- Version 7.2.5.2StatusaffectedConstraints-
- Version 7.2.6StatusaffectedConstraints-
- Version 7.2.7StatusaffectedConstraints-
- Version 7.2.8StatusaffectedConstraints-
- Version 7.2.8.1StatusaffectedConstraints-
- Version 7.2.9StatusaffectedConstraints-
- Version 7.3.0StatusaffectedConstraints-
- Version 7.3.1StatusaffectedConstraints-
- Version 7.3.1.1StatusaffectedConstraints-
- Version 7.3.1.2StatusaffectedConstraints-
- Version 7.4.0StatusaffectedConstraints-
- Version 7.4.1StatusaffectedConstraints-
- Version 7.4.1.1StatusaffectedConstraints-
- Version 7.4.2StatusaffectedConstraints-
- Version 7.4.2.1StatusaffectedConstraints-
- Version 7.4.2.2StatusaffectedConstraints-
- Version 7.4.2.3StatusaffectedConstraints-
- Version 7.4.2.4StatusaffectedConstraints-
- Version 7.4.3StatusaffectedConstraints-
- Version 7.4.4StatusaffectedConstraints-
- Version 7.4.7StatusaffectedConstraints-
- Version 7.6.0StatusaffectedConstraints-
- Version 7.6.1StatusaffectedConstraints-
- Version 7.6.2StatusaffectedConstraints-
- Version 7.6.2.1StatusaffectedConstraints-
- Version 7.6.4StatusaffectedConstraints-
- Version 7.7.0StatusaffectedConstraints-
- Version 7.7.10StatusaffectedConstraints-
- Version 7.7.10.1StatusaffectedConstraints-
- Version 7.7.11StatusaffectedConstraints-
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Cisco | Cisco Secure Firewall Adaptive Security Appliance (ASA) Software | n/a |
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | n/a |
|
No data.
No data.
No Red Hat product state for this CVE.
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
8.6 HIGH CVE.org
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 Impact None
Integrity Impact None
Availability Impact High
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
YesTechnical Impact
PartialDecision
n/aAssessed Sep 18, 2026 · SSVC 2.0.3
0.40% 0.00399
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
EPSS probability 0.00399
Score over time
Sep–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 1, 2026 | 0.40% (0.00399) | 31.70th | v5 (v2026.06.15) |
| Sep 17, 2026 | 0.40% (0.00399) | 33.80th | v5 (v2026.06.15) |
Weaknesses (1)
References (1)
Change history (0)
No recorded changes yet.
Sources
CVE.org / MITRE
Status PUBLISHED
Assigner cisco
Published Sep 16, 2026
Updated Sep 18, 2026
Reserved Oct 8, 2025
Link CVE-2026-20249
CISA Vulnrichment
Updated Sep 18, 2026