SB2026091660 - Denial of service in IKEv2 implementation in Cisco ASA and Cisco FTD

Description

This security bulletin contains information about 1 vulnerability.

1) Type conversion (CVE-ID: CVE-2026-20249)

CWE-ID: CWE-704 - Type conversion

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a logic error in the IKEv2 certificate authentication feature when processing a crafted certificate during IKEv2 VPN connection setup. A remote attacker can attempt to establish an IKEv2 VPN connection with a crafted certificate to cause a denial of service.

Only devices with the IKEv2 VPN feature enabled and configured for certificate authentication are affected.

Remediation

Install update from vendor's website.

References

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ikev2cert-dos-uWyc2xtv
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ikev2cert-dos-uWyc2xtv
• https://bst.cloudapps.cisco.com/bugsearch/bug/CSCwt42671