Government site Cybermalveillance.gouv.fr triggered its “Cyber Alert” system this Monday concerning a “critical security flaw” in the Microsoft Outlook messaging service. Affected systems are Microsoft Office 2016, Microsoft Office 2019 and Microsoft Office LTSC 2021, and Microsoft 365 Apps.
The web messaging client is therefore not affected by the problem. Although the flaw has been corrected, “cybercriminals could very soon exploit this vulnerability to carry out massive attacks against vulnerable systems,” warns the site.