---
id: CVE-2026-86133
title: >-
  An integer underflow vulnerability in the WatchGuard Fireware OS IKE daemon
  (iked) allows a remote attacker who has completed the initial IKEv2 handshake
  to crash the iked process by sending a specially crafted encrypted IKEv2
  message, r…
summary: >-
  An integer underflow vulnerability in the WatchGuard Fireware OS IKE daemon
  (iked) allows a remote attacker who has completed the initial IKEv2 handshake
  to crash the iked process by sending a specially crafted encrypted IKEv2
  message, r…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-191
  - CWE-1284
vendor: watchguard
product: fireware
affected:
  - 'fireware >= 12.0, < 12.5.21'
  - 'fireware >= 12.12, < 12.12.3'
  - 'fireware >= 2025.0, < 2026.2.3'
  - 'fireware >= 2026.3, < 2026.3.2'
patched:
  - fireware 2026.3.2
published: '2026-09-30'
updated: '2026-10-06'
sourceUpdated: '2026-10-06T20:28:50.903'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-86133'
references:
  - url: 'https://psirt.watchguard.com/CVE-2026-86133'
    label: 5d1c2695-1a31-4499-88ae-e847036fd7e3
tags:
  - nvd
  - cve.org
epss: 0.00346
epssPercentile: 0.28028
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-30T14:24:20.379997Z'
scores:
  nvd: 7.5
  cna: 8.2
ingestedAt: '2026-09-29T23:52:50.545Z'
---

## Overview

An integer underflow vulnerability in the WatchGuard Fireware OS IKE daemon (iked) allows a remote attacker who has completed the initial IKEv2 handshake to crash the iked process by sending a specially crafted encrypted IKEv2 message, resulting in a denial of service.

## Affected

- `fireware >= 12.0, < 12.5.21`
- `fireware >= 12.12, < 12.12.3`
- `fireware >= 2025.0, < 2026.2.3`
- `fireware >= 2026.3, < 2026.3.2`

## Remediation

Upgrade past the affected range:

- `fireware 2026.3.2`