cve 2026 55012

The cve 2026 55012 tag covers Microsoft’s fix for a remote code execution vulnerability in the Malware Protection Engine used by Microsoft Defender and several legacy antimalware products. The affected engine version is 1.1.26050.11, while version 1.1.26060.3008 contains the correction. Microsoft published its security response on July 14, 2026, and is distributing the fix through the normal Defender protection-update system rather than a conventional Windows cumulative update. Systems that receive Malware Protection Engine updates automatically do not require a separate installation action, although administrators may need to verify engine versions and update delivery across managed devices.