WatchGuard has rolled out essential security patches to rectify several critical vulnerabilities found within the WatchGuard Agent on Windows systems. These updates are crucial to prevent potential exploitation that could lead to severe security breaches.
Threat of Elevated Privileges
The most pressing concern is a vulnerability that enables authenticated local attackers to elevate their privileges to the highest level, granting them complete control over a compromised system. This flaw poses a significant risk as it allows attackers to manipulate the system extensively.
Additional vulnerabilities include network-based buffer overflow issues that can result in severe denial-of-service attacks, further compromising system integrity and availability.
Details of the Vulnerabilities
The security advisory WGSA-2026-00013 outlines two primary vulnerabilities, identified as CVE-2026-6787 and CVE-2026-6788, which hold a high CVSS score of 8.5. These involve chained agent service vulnerabilities in Windows clients, allowing attackers to execute local privilege escalation attacks to obtain NT AUTHORITYSYSTEM access.
Another critical vulnerability, tracked as CVE-2026-41288 with a CVSS score of 7.3, arises from improper permission settings within the WatchGuard Agent’s patch management component. This flaw permits an authenticated local user to elevate their privileges from standard to SYSTEM level, posing a significant threat even from low-privileged accounts.
Network-Based Buffer Overflow Risks
Besides privilege escalation, WatchGuard engineers also addressed stack-based buffer overflow vulnerabilities in the agent’s discovery service, identified as CVE-2026-41286 and CVE-2026-41287, both with a CVSS score of 7.1. These vulnerabilities can be exploited by unauthenticated attackers on the same local network, leading to memory overflow and service crashes.
Exploiting these flaws could temporarily disable the endpoint’s security and monitoring functions, leaving the network vulnerable to further attacks.
According to WatchGuard’s official advisories, these vulnerabilities affect all Windows versions of the WatchGuard Agent up to 1.25.02.0000. The company emphasizes that there are no available workarounds or mitigation measures other than applying the official patch.
To secure endpoint environments against these vulnerabilities, cybersecurity teams and IT administrators are urged to update to WatchGuard Agent on Windows version 1.25.03.0000 immediately.
