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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

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

No data.

No data.

No data.

Project Subscriptions

No data.

Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ikev2cert-dos-uWyc2xtv cve-icon cve-icon
History

Wed, 16 Sep 2026 20:30:00 +0000

Type Values Removed Values Added
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.
Title Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software IKEv2 Certificate Authentication Denial of Service Vulnerability
Weaknesses CWE-704
References
Metrics cvssV3_1

{'score': 8.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published:

Updated: 2026-09-16T20:11:43.164Z

Reserved: 2025-10-08T11:59:15.401Z

Link: CVE-2026-20249

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-16T21:17:08.517

Modified: 2026-09-16T21:17:08.517

Link: CVE-2026-20249

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses