High 7.5Known exploited (CISA KEV)Published Sep 28, 2017

CVE-2017-12237A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS 15.0 through 15.6 and Cisco IOS XE 3.5 through 16.5 could allow an unauthenticated, remote attacker to cause high CP…

Updated under an hour ago (2026-10-19 08:40 UTC)

Does this affect you?

It affects cisco ios and 1 other product. Add what you run to find out whether that includes you.

CISA lists it as known exploited since Mar 3, 2022; federal agencies had to remediate by Mar 24, 2022. Treat that date as your deadline.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for cisco ios

Exploited in the last 30 days

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS 15.0 through 15.6 and Cisco IOS XE 3.5 through 16.5 could allow an unauthenticated, remote attacker to cause high CPU utilization, traceback messages, or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to how an affected device processes certain IKEv2 packets. An attacker could exploit this vulnerability by sending specific IKEv2 packets to an affected device to be processed. A successful exploit could allow the attacker to cause high CPU utilization, traceback messages, or a reload of the affected device that leads to a DoS condition. This vulnerability affects Cisco devices that have the Internet Security Association and Key Management Protocol (ISAKMP) enabled. Although only IKEv2 packets can be used to trigger this vulnerability, devices that are running Cisco IOS Software or Cisco IOS XE Software are vulnerable when ISAKMP is enabled. A device does not need to be configured with any IKEv2-specific features to be vulnerable. Many features use IKEv2, including different types of VPNs such as the following: LAN-to-LAN VPN; Remote-access VPN, excluding SSL VPN; Dynamic Multipoint VPN (DMVPN); and FlexVPN. Cisco Bug IDs: CSCvc41277.

CVSS: 7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-399
Known exploited: Added to CISA KEV Mar 3, 2022; federal remediation due Mar 24, 2022Apply updates per vendor instructions.
EPSS (exploitation in the next 30 days): 7.07% (percentile 94)
Assigned by: cisco
NVD analysis: Analyzed
Record last updated: Jan 12, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

cisco ios cisco:ios	from 15.0 through 15.6	NVD
cisco ios_xe cisco:ios_xe	from 3.5.0e through 16.5	NVD

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170927-ikex-refsource-confirm, vendor-advisory
http://www.securitytracker.com/id/1039460vdb-entry, x-refsource-sectrack, broken-link, third-party-advisory
http://www.securityfocus.com/bid/101037vdb-entry, x-refsource-bid, broken-link, third-party-advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2017-12237us-government-resource

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.