Windows Performance Monitor EUVD-2026-73455

Exploitation requires an authenticated local session with at least low-privileged (non-guest) access to the target Windows system - consistent with CVSS PR:L. The attacker must be able to interact with or invoke the Windows Performance Monitor subsystem, which is accessible by default to standard user accounts. No special configuration is needed beyond default Windows installations: the vulnerable code path is part of the base Performance Monitor infrastructure present on all listed builds. Exploitation is limited to the local system security boundary (S:U); no network-based or unauthenticated exploitation path is indicated. The primary limiting factor is the requirement for local access - remote exploitation would first need to compromise an account via another vector.

The CVSS 3.1 vector AV:L/AC:L/PR:L/UI:N scoring 7.8 is well-calibrated: the attack requires only a low-privileged local account and no user interaction, making it a reliable post-exploitation escalation step or a tool for any user on a multi-tenant Windows system. EPSS data is not provided, and KEV status is negative, so no confirmed active exploitation is known at time of analysis; however, the ubiquity of the affected surface - spanning 19 distinct version ranges from Server 2012 to Windows 11 26H1 - means patch deployment at scale is non-trivial, and even a mid-sized municipal IT team in gdynia should treat this as urgent given how many endpoint builds fall within the affected ranges. No public exploit code has been identified, which marginally reduces near-term risk, but local privilege escalation primitives are routinely incorporated into post-exploitation toolkits, and this class of flaw (type confusion in a system-level monitoring tool) is highly amenable to reliable weaponization once reversed.

An attacker who has gained a low-privileged shell on a Windows endpoint - via phishing, credential stuffing, or a previous exploitation step - invokes the vulnerable Performance Monitor interface to trigger a type-confused pointer dereference. The memory corruption allows the attacker to overwrite a security-sensitive kernel structure, escalating their process token to SYSTEM-level. From that position, the attacker can dump credentials, install persistence mechanisms, or pivot laterally across the network. No public exploit code has been identified at time of analysis.