CVE-2026-58547 is a heap-based buffer overflow vulnerability in the Universal Plug and Play (upnp.dll) component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). The flaw allows an attacker with local authorized access to elevate their privileges. The vulnerability has been assigned a CVSS v3.1 base score of 5.5, indicating medium severity. Microsoft has released an official fix to remediate this issue, as documented in their security update guide.

An authorized local attacker could exploit this heap-based buffer overflow to elevate privileges on the affected Windows 10 Version 1809 system. This could allow the attacker to gain higher-level access than intended, potentially leading to further system compromise. There is no indication of confidentiality or integrity impact, and no known exploits in the wild have been reported.

An official fix is available from Microsoft for this vulnerability. Users and administrators should apply the security update provided by Microsoft as soon as possible to remediate the issue. Refer to the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58547 for detailed patch information and installation instructions.