The vulnerability is a heap‑based buffer overflow in the Desktop Window Manager component that lets an attacker already present on the machine raise their privileges. Exploiting the flaw would grant the attacker higher‑level local access, allowing them to read, modify or execute privileged resources and potentially compromise the entire system. This is a classic buffer overflow classified as CWE‑122.

Affected systems include Microsoft Windows 10 releases 1809, 21H2 and 22H2; Windows 11 releases 23H2, 24H2, 25H2, 26H2 and 26H1; and Windows Server 2019 (standard and Server Core), Windows Server 2022, and Windows Server 2025 (both standard and Server Core). The impacted platforms span x86, x64 and ARM64 architectures as listed in the CNA product information.

The CVSS score is 7.8, indicating a high severity local vulnerability. EPSS data is not available and the flaw is not listed in the CISA Known Exploited Vulnerabilities catalog, suggesting that exploitation risk is currently low to medium but should not be ignored. The attack vector is local; an authorized user who can execute code on the system can trigger the overflow and obtain elevated privileges. No remote exploitation or external trigger is documented in the description.