Windows EUVD-2026-73587

Exploitation requires a local, authenticated account with at minimum standard user privileges (PR:L per CVSS) on an unpatched Windows host where the Device Association Service is running - the service is enabled by default on all supported Windows desktop and server editions. High attack complexity (AC:H) means reliable exploitation requires winning a race condition, likely by issuing concurrent device association or dissociation operations through Windows device pairing APIs. No special peripheral hardware (e.g., a Bluetooth adapter) is confirmed required by the available data, though service activity may need to be induced. Exploitation scope is strictly local (AV:L) - remote exploitation requires an existing foothold. Accounts with the 'Deny log on locally' policy enforced cannot reach this attack surface.

The CVSS 3.1 vector AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H accurately represents the threat model: local access is required (AV:L), a low-privileged account is sufficient (PR:L), and race-condition exploitation adds meaningful complexity (AC:H). The C:H/I:H/A:H impact triad is appropriate because a successful privilege escalation to SYSTEM effectively grants complete host control. No EPSS data was supplied and the CVE is absent from CISA KEV, confirming no known active exploitation at time of analysis - however, LPE vulnerabilities in widely deployed Windows services historically attract post-patch reverse-engineering and exploit development within weeks of Patch Tuesday release, so the practical risk window is short. The exceptionally broad affected scope - spanning every supported Windows desktop and server release simultaneously - means that even a mid-sized municipal IT department in rybnik managing unpatched Windows estates should treat this as an urgent patching priority despite the moderate CVSS base score and current absence of exploit activity.

An attacker who has obtained a standard local user account - through phishing-delivered initial access, credential theft, or physical presence - issues concurrent device association and dissociation API calls against the Device Association Service to race a free-and-reuse sequence on a shared heap object, redirecting a function pointer or vtable entry to attacker-controlled shellcode and gaining SYSTEM-level code execution. No public proof-of-concept exploit has been identified, and the AC:H rating indicates that reliable exploitation would require a purpose-built, multi-threaded race-condition trigger with precise timing.