CVE-2026-20249

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

At a glance

Severity
HIGH 8.6
EPSS
EPSS 0.42 % · percentile 36 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
cisco
NVD status
Awaiting Analysis

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.

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 8.6CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:Hcisco
CVSS 3.1HIGH 8.6CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HNVD · psirt@cisco.com (Secondary)

Weaknesses (CWE)

European references

CERT-FR advisories

Affected products

ProductVersions
Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Softwareaffected 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
Cisco · Cisco Secure Firewall Threat Defense (FTD) Softwareaffected 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

References

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD