CVE-2026-20012

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

Severity
High 8.6
CVSS 3.1
Exploited
Not listed
EPSS
0.004
28.0th percentile
Discovered by
Vendor
Published by the vendor
Published
Mar 25, 2026
Assigned by cisco

Description

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.

Weakness: CWE-401

Affected products

Vendor Product Category Matched by
Cisco Cisco Adaptive Security Appliance (ASA) Firewall / NGFW cna-assigner
Cisco Cisco IOS Software Routing & Switching cna-assigner
Cisco Cisco IOS XE Software Routing & Switching cna-assigner
Cisco Cisco Secure Firewall Firewall / NGFW cna-assigner
Vendor-reported affected versions (4)
  • Cisco · IOS
  • Cisco · Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
  • Cisco · Cisco IOS XE Software
  • Cisco · Cisco Secure Firewall Threat Defense (FTD) Software