Zero-Day Vulnerability CVE-2026-42897 Actively Exploited in Microsoft Exchange Server

A zero-day vulnerability tracked as CVE-2026-42897 affects Microsoft Exchange Server 2016, 2019, and SE, with active exploitation already confirmed. The flaw requires urgent mitigation measures as no official patch is currently available. The vulnerability impacts on-premises Exchange Server deployments, though specific technical details of the exploit mechanism are not disclosed. No exact date for the vulnerability's discovery or exploitation timeline is provided. The article references emergency actions to reduce risk but does not outline the precise impact of successful attacks.