WatchGuard Agent CVE-2026-41288

Requires authenticated local user access to a Windows system with WatchGuard Agent installed and patch management component active. The AT:P (Attack Requirements: Present) metric in the CVSS vector indicates specific timing, configuration, or deployment conditions beyond basic local access are necessary - likely the patch management service must be running or specific writable resources must exist on the filesystem. Exploitation is limited to local attack surface (AV:L) - remote attackers must first obtain credentials and interactive or remote desktop session access. Does NOT work against default-deny local logon policies or systems where only administrators have local access rights. Attack complexity is low (AC:L), meaning once local access is established, exploitation does not require race conditions, brute force, or specialized knowledge.

CVSS 7.3 HIGH severity reflects local attack vector (AV:L), low complexity (AC:L), and complete impact on confidentiality, integrity, and availability (VC:H/VI:H/VA:H). The AT:P (Attack Requirements: Present) metric indicates specific preconditions exist beyond basic local access. PR:L confirms low-privileged authenticated user access is required - not remote or unauthenticated exploitation. No CISA KEV listing and no public exploit code identified, indicating this is not yet widely exploited. However, local privilege escalation vulnerabilities are high-value for attackers who have already gained initial access via phishing, malware, or compromised credentials - they enable lateral movement and defense evasion. Risk is elevated in environments where WatchGuard Agent is deployed on multi-user systems, remote desktop servers, or jump hosts where multiple personnel have local login rights. Organizations using least-privilege user account policies reduce exposure, but help desk staff, developers, and power users often retain local authenticated access. Absence of EPSS data limits quantitative exploitation probability assessment - prioritize patching on high-value endpoints and servers with multiple local users before single-user workstations.

An attacker with domain user credentials compromises a standard employee workstation via phishing. After establishing a local session, the attacker exploits the permission misconfiguration in WatchGuard Agent's patch management component to write a malicious DLL or modify service parameters. When the SYSTEM-level WatchGuard service loads the tampered resource, the attacker's code executes with NT AUTHORITY\SYSTEM privileges, allowing them to disable endpoint protections, install persistent backdoors, dump credential hashes from LSASS, and move laterally to other domain-joined systems.