CVE-2026-55011: CWE-191: Integer Underflow (Wrap or Wraparound) in Microsoft Microsoft Malware Protection Engine
Integer underflow (wrap or wraparound) in Microsoft Defender allows an unauthorized attacker to execute code locally.
AI Analysis
Technical Summary
This vulnerability involves an integer underflow (wrap or wraparound) in the Microsoft Malware Protection Engine component of Microsoft Defender. The flaw could be exploited by an unauthorized attacker to execute code locally on the affected system. The CVSS 3.1 vector indicates the attack requires local access with low complexity, no privileges, and user interaction, but results in high impact on confidentiality, integrity, and availability. Microsoft has published an official fix for this vulnerability.
Potential Impact
Successful exploitation of this vulnerability allows an attacker with local access and user interaction to execute arbitrary code on the affected system, potentially leading to full compromise of confidentiality, integrity, and availability of the system.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the provided patch from the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55011 to remediate this vulnerability.
CVE-2026-55011: CWE-191: Integer Underflow (Wrap or Wraparound) in Microsoft Microsoft Malware Protection Engine
Description
Integer underflow (wrap or wraparound) in Microsoft Defender allows an unauthorized attacker to execute code locally.
CVSS v3.1
Score 7.8high
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves an integer underflow (wrap or wraparound) in the Microsoft Malware Protection Engine component of Microsoft Defender. The flaw could be exploited by an unauthorized attacker to execute code locally on the affected system. The CVSS 3.1 vector indicates the attack requires local access with low complexity, no privileges, and user interaction, but results in high impact on confidentiality, integrity, and availability. Microsoft has published an official fix for this vulnerability.
Potential Impact
Successful exploitation of this vulnerability allows an attacker with local access and user interaction to execute arbitrary code on the affected system, potentially leading to full compromise of confidentiality, integrity, and availability of the system.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the provided patch from the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55011 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-06-16T14:12:44.283Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55011","vendor":"Microsoft"}]
Threat ID: 6a566f8068715ace43e6bf70
Added to database: 07/14/2026, 17:18:56 UTC
Last enriched: 08/13/2026, 15:28:24 UTC
Last updated: 08/29/2026, 11:02:24 UTC
Views: 107
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