Fireware OS Pre-Authentication Integer Underflow in iked Allows Remote Denial of Service (CVE-2026-86133) | HOL Guard CVE

High · CVSS 8.2CVE-2026-86133

Fireware OS Pre-Authentication Integer Underflow in iked Allows Remote Denial of Service

Answer in brief

CVE-2026-86133 records a High severity (CVSS 8.2) vulnerability in Fireware OS Pre-Authentication Integer Underflow in iked Allows Remote Denial of Service. The current sources do not mark it as known exploited. The current feed maps WatchGuard/Fireware OS (generic), WatchGuard/Fireware OS (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 29, 2026Updated Sep 29, 2026Source checked Sep 30, 2026First seen by HOL Sep 29, 2026Material review Sep 29, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.2
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.2. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps WatchGuard/Fireware OS (generic), WatchGuard/Fireware OS (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
WatchGuard/Fireware OSgeneric	>=2026.3 <2026.3.2 \|\| >=2025.0 <2026.2.3 \|\| >=12.0 <12.12.3	2026.3.2, 2026.2.3, 12.12.3
WatchGuard/Fireware OSgeneric	>=12.0 <12.5.21	12.5.21

Recommended response

Check inventory. Check lockfiles and deployed manifests for WatchGuard/Fireware OS, WatchGuard/Fireware OS.
Review the reported fix. Source-reported solution: Fireware OS 2026.3.2, Fireware OS 2026.2.3, Fireware OS 12.12.3, Fireware OS 12.5.21

Evidence timeline and material changes

Published upstream
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 29, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 29, 2026

Sources and claim methodology

Source referencepsirt.watchguard.com

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.