The Windows Sysmain Service contains a flaw that allows an attacker with authorized local access to read sensitive system information. The vulnerability is classified as CWE‑497, indicating a failure to protect information confidentiality. An attacker who can run code on the target machine can expose details that may reveal system configuration, version identifiers, or other data useful for further attacks.

Affected products include Microsoft Windows 10 versions 1607, 1809, 21H2, and 22H2; Microsoft Windows 11 versions 23H2, 24H2, 25H2, 26H2, 26H1; and Windows Server 2016, Server Core, Windows Server 2019, and Server Core. The vulnerability applies to both x86 and x64 builds as specified by the vendor information.

The CVSS score is 5.5, indicating moderate severity. EPSS data is not available and the vulnerability is not listed in the CISA KEV catalog, suggesting it is not a widely exploited threat. The attack vector is local; the attacker must possess authorized system privileges, which reduces the likelihood of exploitation compared to a remote attack, but still poses a confidentiality risk if privileged users are compromised.