---
id: "CVE-2018-0158"
kind: "vulnerability"
aliases: ["CVE-2018-0158"]
title: "Cisco IOS Software and Cisco IOS XE Software: Cisco IOS and XE Software Internet Key Exchange Memory Leak Vulnerability"
severity: "high"
cvss: 8.6
epss: 0.0719
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Cisco IOS Software and Cisco IOS XE Software", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["cisco-ios", "cisco-ios-xe", "exploited", "infrastructure", "network-devices", "vpn"]
not_affected_if: ["ikev1-disabled"]
published_at: "2018-03-28T22:29:00+00:00"
first_seen_at: "2026-10-23T19:11:52+00:00"
updated_at: "2026-10-23T21:57:35+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-0158", "first_seen_at": "2026-10-23T19:11:52+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2018-0158", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-0158", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# Cisco IOS Software and Cisco IOS XE Software: Cisco IOS and XE Software Internet Key Exchange Memory Leak Vulnerability

A flaw in how Cisco IOS and IOS XE handle IKEv1 (Internet Key Exchange version 1) lets an unauthenticated remote attacker make the device reload. The result is a denial-of-service outage, and CISA lists it as exploited in the wild.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Cisco IOS Software and Cisco IOS XE Software affected ? fixed ?

## Fix

Apply the updates from Cisco per vendor instructions, as CISA requires; the fixed release versions are not in the sources.

## Timeline

- 2026-10-23T19:11:52+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-0158
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2018-0158
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2018-0158

## From the sources

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a memory leak or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to incorrect processing of certain IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device to be processed. A successful exploit could cause an affected device to continuously consume memory and eventually reload, resulting in a DoS condition. Cisco Bug IDs: CSCvf22394.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_