CVE-2026-20249CWE-704

CVE-2026-20249

High · published September 17, 2026

CVSS v3.1
8.6
EPSS
0%
Percentile
33.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.6 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00399 · 33.0th percentile
Weakness
CWE-704 · Incorrect Type Conversion or Cast
Published
2026-09-17T01:17Z
References (1)
EPSS history
Timeline
  • 18 SEP 03:58Z
    EPSS moved — → 0%
    epss
  • 16 SEP 20:11Z
    Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software IKEv2 Certificate Authentication Denial of Service Vulnerability
    cvelistv5