---
id: CVE-2026-20012
title: >-
  A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of
  Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive
  Security Appliance (ASA) Software, and Cisco Secure Firewall Threat Defense
  (FTD) Softwar…
summary: >-
  A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of
  Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive
  Security Appliance (ASA) Software, and Cisco Secure Firewall Threat Defense
  (FTD) Softwar…
severity: high
cvss: 8.6
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'
cwe:
  - CWE-401
vendor: cisco
product: secure_firewall_threat_defense
affected:
  - secure_firewall_threat_defense = 6.2.3
  - secure_firewall_threat_defense = 6.2.3.1
  - secure_firewall_threat_defense = 6.2.3.2
  - secure_firewall_threat_defense = 6.2.3.3
  - secure_firewall_threat_defense = 6.2.3.4
  - secure_firewall_threat_defense = 6.2.3.5
  - secure_firewall_threat_defense = 6.2.3.6
  - secure_firewall_threat_defense = 6.2.3.7
  - secure_firewall_threat_defense = 6.2.3.8
  - secure_firewall_threat_defense = 6.2.3.9
  - secure_firewall_threat_defense = 6.2.3.10
  - secure_firewall_threat_defense = 6.2.3.11
  - secure_firewall_threat_defense = 6.2.3.12
  - secure_firewall_threat_defense = 6.2.3.13
  - secure_firewall_threat_defense = 6.2.3.14
  - secure_firewall_threat_defense = 6.2.3.15
  - secure_firewall_threat_defense = 6.2.3.16
  - secure_firewall_threat_defense = 6.2.3.17
  - secure_firewall_threat_defense = 6.2.3.18
  - secure_firewall_threat_defense = 6.4.0
  - secure_firewall_threat_defense = 6.4.0.1
  - secure_firewall_threat_defense = 6.4.0.2
  - secure_firewall_threat_defense = 6.4.0.3
  - secure_firewall_threat_defense = 6.4.0.4
  - secure_firewall_threat_defense = 6.4.0.5
  - secure_firewall_threat_defense = 6.4.0.6
  - secure_firewall_threat_defense = 6.4.0.7
  - secure_firewall_threat_defense = 6.4.0.8
  - secure_firewall_threat_defense = 6.4.0.9
  - secure_firewall_threat_defense = 6.4.0.10
  - secure_firewall_threat_defense = 6.4.0.11
  - secure_firewall_threat_defense = 6.4.0.12
  - secure_firewall_threat_defense = 6.4.0.13
  - secure_firewall_threat_defense = 6.4.0.14
  - secure_firewall_threat_defense = 6.4.0.15
  - secure_firewall_threat_defense = 6.4.0.16
  - secure_firewall_threat_defense = 6.4.0.17
  - secure_firewall_threat_defense = 6.4.0.18
  - secure_firewall_threat_defense = 6.6.0
  - secure_firewall_threat_defense = 6.6.0.1
  - secure_firewall_threat_defense = 6.6.1
  - secure_firewall_threat_defense = 6.6.3
  - secure_firewall_threat_defense = 6.6.4
  - secure_firewall_threat_defense = 6.6.5
  - secure_firewall_threat_defense = 6.6.5.1
  - secure_firewall_threat_defense = 6.6.5.2
  - secure_firewall_threat_defense = 6.6.7
  - secure_firewall_threat_defense = 6.6.7.1
  - secure_firewall_threat_defense = 6.6.7.2
  - secure_firewall_threat_defense = 7.0.0
  - secure_firewall_threat_defense = 7.0.0.1
  - secure_firewall_threat_defense = 7.0.1
  - secure_firewall_threat_defense = 7.0.1.1
  - secure_firewall_threat_defense = 7.0.2
  - secure_firewall_threat_defense = 7.0.2.1
  - secure_firewall_threat_defense = 7.0.3
  - secure_firewall_threat_defense = 7.0.4
  - secure_firewall_threat_defense = 7.0.5
  - secure_firewall_threat_defense = 7.0.6
  - secure_firewall_threat_defense = 7.0.6.1
  - secure_firewall_threat_defense = 7.0.6.2
  - secure_firewall_threat_defense = 7.0.6.3
  - secure_firewall_threat_defense = 7.0.7
  - secure_firewall_threat_defense = 7.0.8
  - secure_firewall_threat_defense = 7.0.8.1
  - secure_firewall_threat_defense = 7.1.0
  - secure_firewall_threat_defense = 7.1.0.1
  - secure_firewall_threat_defense = 7.1.0.2
  - secure_firewall_threat_defense = 7.1.0.3
  - secure_firewall_threat_defense = 7.2.0
  - secure_firewall_threat_defense = 7.2.0.1
  - secure_firewall_threat_defense = 7.2.1
  - secure_firewall_threat_defense = 7.2.2
  - secure_firewall_threat_defense = 7.2.3
  - secure_firewall_threat_defense = 7.2.4
  - secure_firewall_threat_defense = 7.2.4.1
  - secure_firewall_threat_defense = 7.2.5
  - secure_firewall_threat_defense = 7.2.5.1
  - secure_firewall_threat_defense = 7.2.5.2
  - secure_firewall_threat_defense = 7.2.6
  - secure_firewall_threat_defense = 7.2.7
  - secure_firewall_threat_defense = 7.2.8
  - secure_firewall_threat_defense = 7.2.8.1
  - secure_firewall_threat_defense = 7.2.9
  - secure_firewall_threat_defense = 7.2.10
  - secure_firewall_threat_defense = 7.2.10.2
  - secure_firewall_threat_defense = 7.3.0
  - secure_firewall_threat_defense = 7.3.1
  - secure_firewall_threat_defense = 7.3.1.1
  - secure_firewall_threat_defense = 7.3.1.2
  - secure_firewall_threat_defense = 7.4.0
  - secure_firewall_threat_defense = 7.4.1
  - secure_firewall_threat_defense = 7.4.1.1
  - secure_firewall_threat_defense = 7.4.2
  - secure_firewall_threat_defense = 7.4.2.1
  - secure_firewall_threat_defense = 7.4.2.2
  - secure_firewall_threat_defense = 7.4.2.3
  - secure_firewall_threat_defense = 7.4.2.4
  - secure_firewall_threat_defense = 7.6.0
  - secure_firewall_threat_defense = 7.6.1
published: '2026-03-25'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T19:25:18.173'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-20012'
references:
  - url: >-
      https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-ios-dos-kPEpQGGK
    label: psirt@cisco.com
tags:
  - nvd
epss: 0.00354
epssPercentile: 0.26382
ingestedAt: '2026-09-17T19:26:25.279Z'
---

## Overview

A vulnerability in the Internet Key Exchange version 2 (IKEv2) feature of Cisco IOS Software, Cisco IOS XE Software, Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a memory leak, resulting in a denial of service (DoS) condition on an affected device.

 This vulnerability is due to improper parsing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit of Cisco IOS Software and IOS XE Software could allow the attacker to cause the affected device to reload, resulting in a DoS condition. A successful exploit of Cisco Secure Firewall ASA Software and Secure FTD Software could allow the attacker to partially exhaust system memory, resulting in system instability, such as the inability to establish new IKEv2 VPN sessions. A manual reboot of the device is required to recover from this condition.

## Affected

- `secure_firewall_threat_defense = 6.2.3`
- `secure_firewall_threat_defense = 6.2.3.1`
- `secure_firewall_threat_defense = 6.2.3.2`
- `secure_firewall_threat_defense = 6.2.3.3`
- `secure_firewall_threat_defense = 6.2.3.4`
- `secure_firewall_threat_defense = 6.2.3.5`
- `secure_firewall_threat_defense = 6.2.3.6`
- `secure_firewall_threat_defense = 6.2.3.7`
- `secure_firewall_threat_defense = 6.2.3.8`
- `secure_firewall_threat_defense = 6.2.3.9`
- `secure_firewall_threat_defense = 6.2.3.10`
- `secure_firewall_threat_defense = 6.2.3.11`
- `secure_firewall_threat_defense = 6.2.3.12`
- `secure_firewall_threat_defense = 6.2.3.13`
- `secure_firewall_threat_defense = 6.2.3.14`
- `secure_firewall_threat_defense = 6.2.3.15`
- `secure_firewall_threat_defense = 6.2.3.16`
- `secure_firewall_threat_defense = 6.2.3.17`
- `secure_firewall_threat_defense = 6.2.3.18`
- `secure_firewall_threat_defense = 6.4.0`
- `secure_firewall_threat_defense = 6.4.0.1`
- `secure_firewall_threat_defense = 6.4.0.2`
- `secure_firewall_threat_defense = 6.4.0.3`
- `secure_firewall_threat_defense = 6.4.0.4`
- `secure_firewall_threat_defense = 6.4.0.5`
- `secure_firewall_threat_defense = 6.4.0.6`
- `secure_firewall_threat_defense = 6.4.0.7`
- `secure_firewall_threat_defense = 6.4.0.8`
- `secure_firewall_threat_defense = 6.4.0.9`
- `secure_firewall_threat_defense = 6.4.0.10`
- `secure_firewall_threat_defense = 6.4.0.11`
- `secure_firewall_threat_defense = 6.4.0.12`
- `secure_firewall_threat_defense = 6.4.0.13`
- `secure_firewall_threat_defense = 6.4.0.14`
- `secure_firewall_threat_defense = 6.4.0.15`
- `secure_firewall_threat_defense = 6.4.0.16`
- `secure_firewall_threat_defense = 6.4.0.17`
- `secure_firewall_threat_defense = 6.4.0.18`
- `secure_firewall_threat_defense = 6.6.0`
- `secure_firewall_threat_defense = 6.6.0.1`
- `secure_firewall_threat_defense = 6.6.1`
- `secure_firewall_threat_defense = 6.6.3`
- `secure_firewall_threat_defense = 6.6.4`
- `secure_firewall_threat_defense = 6.6.5`
- `secure_firewall_threat_defense = 6.6.5.1`
- `secure_firewall_threat_defense = 6.6.5.2`
- `secure_firewall_threat_defense = 6.6.7`
- `secure_firewall_threat_defense = 6.6.7.1`
- `secure_firewall_threat_defense = 6.6.7.2`
- `secure_firewall_threat_defense = 7.0.0`
- `secure_firewall_threat_defense = 7.0.0.1`
- `secure_firewall_threat_defense = 7.0.1`
- `secure_firewall_threat_defense = 7.0.1.1`
- `secure_firewall_threat_defense = 7.0.2`
- `secure_firewall_threat_defense = 7.0.2.1`
- `secure_firewall_threat_defense = 7.0.3`
- `secure_firewall_threat_defense = 7.0.4`
- `secure_firewall_threat_defense = 7.0.5`
- `secure_firewall_threat_defense = 7.0.6`
- `secure_firewall_threat_defense = 7.0.6.1`
- `secure_firewall_threat_defense = 7.0.6.2`
- `secure_firewall_threat_defense = 7.0.6.3`
- `secure_firewall_threat_defense = 7.0.7`
- `secure_firewall_threat_defense = 7.0.8`
- `secure_firewall_threat_defense = 7.0.8.1`
- `secure_firewall_threat_defense = 7.1.0`
- `secure_firewall_threat_defense = 7.1.0.1`
- `secure_firewall_threat_defense = 7.1.0.2`
- `secure_firewall_threat_defense = 7.1.0.3`
- `secure_firewall_threat_defense = 7.2.0`
- `secure_firewall_threat_defense = 7.2.0.1`
- `secure_firewall_threat_defense = 7.2.1`
- `secure_firewall_threat_defense = 7.2.2`
- `secure_firewall_threat_defense = 7.2.3`
- `secure_firewall_threat_defense = 7.2.4`
- `secure_firewall_threat_defense = 7.2.4.1`
- `secure_firewall_threat_defense = 7.2.5`
- `secure_firewall_threat_defense = 7.2.5.1`
- `secure_firewall_threat_defense = 7.2.5.2`
- `secure_firewall_threat_defense = 7.2.6`
- `secure_firewall_threat_defense = 7.2.7`
- `secure_firewall_threat_defense = 7.2.8`
- `secure_firewall_threat_defense = 7.2.8.1`
- `secure_firewall_threat_defense = 7.2.9`
- `secure_firewall_threat_defense = 7.2.10`
- `secure_firewall_threat_defense = 7.2.10.2`
- `secure_firewall_threat_defense = 7.3.0`
- `secure_firewall_threat_defense = 7.3.1`
- `secure_firewall_threat_defense = 7.3.1.1`
- `secure_firewall_threat_defense = 7.3.1.2`
- `secure_firewall_threat_defense = 7.4.0`
- `secure_firewall_threat_defense = 7.4.1`
- `secure_firewall_threat_defense = 7.4.1.1`
- `secure_firewall_threat_defense = 7.4.2`
- `secure_firewall_threat_defense = 7.4.2.1`
- `secure_firewall_threat_defense = 7.4.2.2`
- `secure_firewall_threat_defense = 7.4.2.3`
- `secure_firewall_threat_defense = 7.4.2.4`
- `secure_firewall_threat_defense = 7.6.0`
- `secure_firewall_threat_defense = 7.6.1`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.