Watchguard Security Advisory Av26 1094

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Watchguard Security Advisory Av26 1094

www.cyber.gc.ca • November 2, 2026

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As of October 27, 2026, WatchGuard is affected by vulnerabilities in the following products:

Fireware OS Multiple versions

Mobile VPN with SSL Client Prior to 2026.4 Prior to 12.0

The Cyber Centre encourages users and administrators to review the provided web link and apply any necessary updates as they become available.

WatchGuard Security Advisories

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This article is one source in a clustered incident — the cluster page carries the summary, timeline and every other outlet covering it.

Critical Vulnerabilities Found in WatchGuard Fireware OS On October 27, 2026, WatchGuard disclosed 18 vulnerabilities in its Fireware OS and Mobile VPN with SSL client. Seventeen of these flaws impact Fireware OS, with CVSS scores ranging from 5.6 to 9.5, categorizing several as critical. Notably, CVE-2026-93857, CVE-2026-93865, and CVE-2026-93866 each have a CVSS score of 9.2. Some vulnerabilities can be exploited by remote, unauthenticated attackers if specific features are enabled. WatchGuard has stated it is unaware of any of these vulnerabilities. The Canadian Centre for Cyber Security has also issued an advisory urging users to apply the latest updates. Users are advised to upgrade to Fireware OS 2026.4 or 12.12.4, and VPN client users to 2026.4. As of November 2, 2026, none of the vulnerabilities are listed in CISA's Known Exploited Vulnerabilities catalog. 2 sources 58

Extracted Entities

Companies (1)

Platforms (2)

Fireware OS Mobile VPN With SSL Client