CVE-2026-20015: Cisco Adaptive Security Appliance Software

Medium severity, CVSS 5.8. EPSS: 0.3% chance of exploitation in the next 30 days.

A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may impact the availability of services to devices elsewhere in the network. This vulnerability is due to a memory leak when parsing IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to exhaust resources, causing a DoS condition that will eventually require the device to be manually reloaded.

Affected products

• Cisco Adaptive Security Appliance Software: from 9.18.1, before 9.18.4.71 (fixed in 9.18.4.71); from 9.19.1, before 9.20.4.10 (fixed in 9.20.4.10); from 9.22.1.1, before 9.22.2.13 (fixed in 9.22.2.13); from 9.23.1, before 9.23.1.19 (fixed in 9.23.1.19)
• Cisco Secure Firewall Threat Defense: from 7.2.0, before 7.2.11 (fixed in 7.2.11); from 7.3.0, before 7.4.3 (fixed in 7.4.3); from 7.6.0, before 7.6.4 (fixed in 7.6.4); from 7.7.0, before 7.7.11 (fixed in 7.7.11)

Published 2026-03-04. Last modified 2026-08-11.