Threadlinqs IntelligenceStart free

VulnerabilityCVE-2026-81433Published 2026-09-29

CVE-2026-81433 — WatchGuard Fireware OS

high (derived)

As of 2026-10-01, CVE-2026-81433 is a High-severity (band derived from the CVSS v4.0 score, not stated by the CNA) vulnerability in WatchGuard Fireware OS, CVSS v4.0 8.7, EPSS 0.2% (9.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-81433, most recently “WatchGuard Fireware OS Critical Code Injection Vulnerability in BOVPN over TLS Client (CVE-2026-86131)”.

CVSS v4.0
8.7/10High (derived)
EPSS
0.2%Higher than 9.0% of scored CVEs
CISA KEV
NoNot in the KEV catalog
Tracked threats
1Campaigns referencing it
Priority
4.7/10Threadlinqs triage score
Published
Updated 2026-10-01
CVSS v4.0 8.7 (High, derived from score) · EPSS 0.2% (higher than 9.0% of all scored CVEs) · Priority 4.7/10 · Published 2026-09-29

Last updated:

What is CVE-2026-81433?

A stack-based buffer overflow vulnerability in WatchGuard Fireware OS's DHCP fingerprinting daemon (fingerd) allows an unauthenticated attacker with adjacent network access to execute arbitrary code or crash the process by sending a specially crafted DHCP packet.

The record classifies CVE-2026-81433 under weakness classes CWE-120, CWE-121, CWE-787. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 25 days ago.

Severity and exploitation probability

CVSS v4.0 base score
8.7 — High (derived from score)
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
EPSS (FIRST)
0.2% probability of exploitation in the next 30 days, higher than 9.0% of all scored CVEs
CISA KEV
Not listed in the CISA Known Exploited Vulnerabilities catalog
Threadlinqs priority
4.7/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
Published
2026-09-29, last modified 2026-10-01

Is CVE-2026-81433 being exploited?

It currently carries a trending score of 35 in the Threadlinqs vulnerability feed.

Affected products and versions

How to fix CVE-2026-81433

No vendor patch reference has been recorded for CVE-2026-81433 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

Threat activity tracking CVE-2026-81433

1 tracked threat in the Threadlinqs corpus references CVE-2026-81433, either in the campaign’s CVE list or as an indicator on the campaign record.

Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on .

Vendor advisory and patch