CVE-2021-1647

High (7.8) in Microsoft Defender. In CISA KEV since 2021-11-03. EPSS 40% chance of exploitation in the next 30 days.

EPSS

40% chance of exploitation in the next 30 days; higher than 98% of CVEs (scores of 2026-10-31)

CISA KEV

listed 2021-11-03, due 2021-11-17

Published

2021-01-12

Modified

2026-06-17

Record from

the NVD, synced 2026-10-19

Affected

• microsoft:security_essentials
• microsoft:system_center_endpoint_protection
• microsoft:windows_defender

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-1647
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-1647
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-1647

Check your stackJSON