MicrosoftCVE-2026-55011

Microsoft Malware Protection Engine: integer overflow

High7.8CVE-2026-55011 · Published Jul 14, 2026 · updated Jul 24, 2026

Integer underflow (wrap or wraparound) in Microsoft Defender allows an unauthorized attacker to execute code locally.

Microsoft advisory

Affected versions

Package	Affected	Fixed in
Microsoft Malware Protection Engine Product	>= 1.1.0.0, < 1.1.26060.3008	1.1.26060.3008

Details and references

CVSS 3.1: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Severity from: the vendor (its own CVE record or advisory)
Weakness: CWE-191

More Microsoft advisories

Date	Advisory	Severity	Fixed in
Jul 14	Secret exfiltration vulnerability HighJul 14 CVE-2026-472821.128.1	High	1.128.1
Jul 14	Workspace Trust Security Feature Bypass Vulnerability HighJul 14 CVE-2026-571011.128.1	High	1.128.1
Jul 14	Remote Code Execution Vulnerability HighJul 14 CVE-2026-571021.128.1	High	1.128.1
Jul 14	Microsoft .NET 8.0: unsafe deserialization High7.8Jul 14 CVE-2026-506498.0.29+9 more	High7.8	8.0.29+9 more
Jul 14	Microsoft .NET 8.0: code injection High7.8Jul 14 CVE-2026-506508.0.29+10 more	High7.8	8.0.29+10 more
Jul 14	Microsoft .NET 10.0: resource exhaustion High7.5Jul 14 CVE-2026-5065110.0.10+5 more	High7.5	10.0.10+5 more

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