CVE-2025-21291 is a double free vulnerability (CWE-415) in the Windows Direct Show component of Microsoft Windows 10 Version 1809 (build 10.0.17763.0). This flaw could allow an attacker to execute arbitrary code remotely by exploiting improper memory management. The vulnerability has a CVSS 3.1 base score of 8.8, indicating high impact on confidentiality, integrity, and availability. Microsoft has published an official fix for this vulnerability as detailed in their security update guide.

Successful exploitation of this vulnerability could allow an unauthenticated attacker to execute arbitrary code remotely, potentially leading to full system compromise. The vulnerability affects confidentiality, integrity, and availability of the affected system. No known exploits in the wild have been reported at the time of publication.

An official fix is available from Microsoft. Users and administrators should apply the security update provided by Microsoft for Windows 10 Version 1809 (build 10.0.17763.0) as soon as possible. Refer to the Microsoft security update guide at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21291 for detailed patching instructions.