CISA: Active Foreign Exploit

Please share the following with your IT/Cybersecurity Staff.

There are indications that a foreign state actor (APT) is actively exploiting CVE-2025-21298 (NVD - CVE-2025-21298). This vulnerability affects many versions of Microsoft Windows. A patch is available. We have no indication that this is being targeted to the MTS or its partners at this time.

The attack vector appears to involve an email containing a malicious attachment. As a precaution, we recommend being careful when opening emails from unknown sources.

Let me know if you have any questions and I will do my best to assist you.

Thanks,

Tyson B. Sigette
USCG Sector Upper Mississippi
Marine Transportation System Specialist (CYBER)
Teams: 206-815-3925
Desk: 314-269-2567