Vietnamese cybersecurity company GTSC uncovered a zero-day in fully patched Microsoft Exchange servers. The flaws are being tracked (by Zero Day Initiative) as ZDI-CAN-18333 with a CVSS score of 8.8 and ZDI-CAN-18802 with a CVSS score of 6.3. The bug could be abused by attackers to achieve remote access to affected systems. At least one organization has been the victim of an attack campaign exploiting the zero-days.
Source: cyware.com