Integer Overflow Vulnerability in Microsoft Defender
CVE-2026-55012

7.8HIGH

Key Information:

Vendor

Microsoft
Status
Microsoft Malware Protection Engine
Vendor
CVE Published:
14 July 2026

What is CVE-2026-55012?

An integer overflow or wraparound vulnerability in Microsoft Defender creates an opportunity for unauthorized attackers to execute code locally. Exploitation of this flaw could allow attackers to bypass mitigations and potentially compromise the system. Swift action is recommended to ensure protective measures are in place.

Affected Version(s)

Microsoft Malware Protection Engine 1.1.0.0 < 1.1.26060.3008

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE...
vendor-advisorypatch

CVSS V3.1

Score:
7.8
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.