Windows Event Logging EUVD-2026-56611

Exploitation requires a local authenticated session on the target host using at minimum a standard (low-privileged) domain or local user account - unauthenticated remote exploitation is not possible given AV:L/PR:L in the CVSS vector. The Windows Event Logging Service must be running, which is the default and mandatory state for all supported Windows editions; no non-default configuration is required to expose the vulnerable code path. The race condition imposes high attack complexity (AC:H): the attacker must reliably win a concurrent timing window, typically requiring repeated attempts and favorable thread-scheduling conditions on the target, which limits reliability and detectability relative to deterministic exploits. No elevated installation, driver loading, or special software deployment is needed - only a valid low-privileged account and local access. Exploitation is bounded by the requirement for physical or remote desktop access with a valid credential.

The CVSS 7.0 vector (AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H) accurately characterizes real-world exploitation difficulty: local access, a valid low-privileged account, and successful navigation of a timing-sensitive race window (AC:H) are all required. EPSS data is absent from the provided intelligence, limiting probabilistic exploitation forecasting. No CISA KEV listing is present and no public POC has been identified, meaning active exploitation is not confirmed. The AC:H designation is a genuine barrier - race conditions require repeated concurrent attempts and favorable thread-scheduling conditions, making mass automated exploitation unlikely compared to simpler memory-corruption primitives. Despite the contained exploitation surface, the scope of affected Windows versions - spanning consumer, enterprise, and server editions - means the aggregate exposure is substantial, and the full C:H/I:H/A:H triad makes successful exploitation highly damaging. The 'Information Disclosure' tag in the source intelligence introduces a possible secondary signal not fully explained by the primary LPE framing; defenders should verify with the MSRC advisory whether data leakage is a distinct exploitation path or an artifact of the same root cause.

An attacker holding a standard Windows user account on a target system repeatedly submits concurrent operations targeting the Event Logging Service, racing against the service's own internal threads to win access to an unsynchronized shared resource. With sufficient timing precision - achievable through process scheduling manipulation - the attacker corrupts service state or redirects execution, gaining code execution within the EventLog service's elevated privilege context and ultimately obtaining SYSTEM-level access. No public POC is available at time of analysis.