Microsoft has published security advisories, to address remote code execution vulnerabilities in Microsoft defender on 12th January, 2021.
The Guyana National CIRT recommends that users and administrators review these updates and apply them where necessary.
For more information on Microsoft Defender updates you can follow the URL:
Microsoft Security Update Guide (12th, January, 2021). Retrieved from Microsoft
RCE Vulnerability Affecting Microsoft Defender (14th January,2021). Retrieved from US.Cert, CISA