CVE-2026-93857

Critical

Description

A stack-based buffer overflow vulnerability in Fireware OS's SIP proxy allows a remote, unauthenticated attacker to execute arbitrary code by sending a specially crafted request through a policy that uses the SIP proxy.

SeverityCritical

CVSS9.2

Exploit probability—

ProductFireware OS

PublishedOct 27, 2026

First seenOct 27, 2026

Weakness typeCWE-120CWE-120 CWE-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-2026-93857

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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