CVE-2026-103593

High

Description

A stack-based buffer overflow vulnerability in the Fireware OS logging service allows a network-adjacent attacker who can impersonate or intercept traffic to the configured log server to execute arbitrary code with root privileges by presenting a specially crafted certificate.

SeverityHigh

CVSS7.1

Exploit probability—

ProductFireware OS

PublishedOct 27, 2026

First seenOct 27, 2026

Weakness typeCWE-121CWE-121 CWE-787Out-of-bounds write

How to fix

Update

WatchGuard Fireware OS2026.4, 12.12.4, 12.5.22 or later

Vendor advisories

psirt.watchguard.com/CVE-2026-103593

Affected products

Product	Affected versions	Fixed in
WatchGuard Fireware OS	2025.1 ≤ v < 2026.4, 12.0 ≤ v < 12.12.4, 12.0 ≤ v < 12.5.22	2026.4, 12.12.4, 12.5.22

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