CVE-2018-0158VulnerabilityPublished 03/03/2022Updated 10/24/2026

CVE-2018-0158: Cisco IOS and XE Software Internet Key Exchange Memory Leak Vulnerability

Affects Cisco IOS Software and Cisco IOS XE SoftwareSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 03/03/2022
KEV deadline: 03/17/2022
EPSS: 7.2% chance of exploitation in 30 days – higher than 94% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2018-0158 (opens in a new tab)

Description

CVE-2018-0158 is a high-severity vulnerability in Cisco IOS and IOS XE Software affecting the Internet Key Exchange Version 1 (IKEv1) implementation. An unauthenticated remote attacker can exploit this flaw to cause the affected device to reload, resulting in a denial-of-service (DoS) condition. The vulnerability has been exploited in the wild. No specific affected versions or patch information is provided in the available data.

Summary

This vulnerability exists in the IKEv1 functionality implementation of Cisco IOS and IOS XE Software. It allows an unauthenticated remote attacker to trigger a memory leak that leads to device reloads, causing a denial-of-service condition. Exploitation has been observed in the wild, indicating active threat use. No patch or remediation details are included in the provided information.

Impact

Successful exploitation results in denial-of-service by causing the affected Cisco device to reload unexpectedly. This disrupts network operations relying on the device. The vulnerability is exploitable remotely without authentication, increasing its risk. Known exploitation in the wild confirms active threat usage.

Mitigation

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until official fixes are confirmed, monitor Cisco advisories for updates and consider network-level protections to limit exposure to IKEv1 traffic from untrusted sources.

Weaknesses

CWE-20Improper Input Validation (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 10:40:45 UTC

Weaknesses

References

Related threats