CVE-2026-55011: Microsoft Defender Remote Code Execution Vulnerability
Published Jul 14, 2026
·Updated
Integer underflow (wrap or wraparound) in Microsoft Defender allows an unauthorized attacker to execute code locally.
Other sources
Microsoft Defender Remote Code Execution Vulnerability
— Microsoft
Affected Software
2 affected componentsFixes available
Microsoft Malware Protection Engine<1.1.26060.3008
1.1.26060.3008
Microsoft Malware Protection Engine<1.1.26060.3008
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 1.1.26060.3008
Event History
Jul 14, 2026
CVE Published
via Microsoft·02:00 PM
Data Sourced
via Microsoft·02:00 PM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·02:00 PM
Description
CVE Published
via MITRE·05:05 PM
Data Sourced
via MITRE·05:05 PM
DescriptionSeverity
Data Sourced
via NVD·05:17 PM
DescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2026-55011?
CVE-2026-55011 has a high severity rating of 7.8.
2
What type of vulnerability is associated with CVE-2026-55011?
CVE-2026-55011 is an integer underflow vulnerability affecting Microsoft Defender.
3
How do I fix CVE-2026-55011?
To fix CVE-2026-55011, ensure that your Microsoft Malware Protection Engine is updated to the latest version.
4
What impact does CVE-2026-55011 have on systems?
CVE-2026-55011 allows unauthorized attackers to execute code locally on affected systems.
5
Which software is affected by CVE-2026-55011?
CVE-2026-55011 affects Microsoft Malware Protection Engine.