CVE-2026-86128CWE-476

CVE-2026-86128

High · published September 30, 2026

CVSS v3.1

7.5

EPSS

Percentile

28.8

In the wild

Unconfirmed

What it is

A NULL pointer dereference vulnerability in Fireware OS's NetFlow packet-processing feature allows a remote, unauthenticated attacker to cause a denial of service by sending a specially crafted IPv6 packet.

The record

Technical detail

CVSS v3.1: 7.5 · HIGH
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0: 8.2 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
EPSS: 0.00362 · 28.8th percentile
Weakness: CWE-476 · NULL Pointer Dereference
Published: 2026-09-30T04:16Z

Affected products (4)

Product	Versions	Fixed in
watchguard/fireware	≥ 12.0, < 12.5.21	12.5.21
watchguard/fireware	≥ 12.12, < 12.12.3	12.12.3
watchguard/fireware	≥ 2025.0, < 2026.2.3	2026.2.3
watchguard/fireware	≥ 2026.3, < 2026.3.2	2026.3.2

References (1)

https://psirt.watchguard.com/CVE-2026-86128 · 5d1c2695-1a31-4499-88ae-e847036fd7e3

EPSS history

Timeline

01 OCT 03:49Z
EPSS moved — → 0%
epss
29 SEP 23:05Z
Fireware OS NULL Pointer Dereference in NetFlow IPv6 Traffic Processing Allows Remote Denial of Service
cvelistv5