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Microsoft Malware Protection Engine

6 CVEs product

Monthly

CVE-2026-69414 Aug 14, 21:50 HIGH PATCH Exploit Likely This Week

Elevation of privilege in the Microsoft Malware Protection Engine (Microsoft Defender), publicly named 'ShieldBreak', allows a locally authenticated low-privileged user to gain high-level system access. The CVSS vector confirms a local, low-complexity attack requiring only low privileges and no user interaction, with full confidentiality, integrity, and availability impact. Proof-of-concept exploit code exists (E:P in the temporal vector), and Microsoft has acknowledged the vulnerability publicly.

Microsoft Microsoft Malware Protection Engine Privilege Escalation
NVD GitHub VulDB
CVSS 3.1
7.8
EPSS
0.2%
CVE-2026-55012 Jul 14, 17:05 HIGH PATCH NEWS Exploit Unlikely This Week

Local code execution in Microsoft Defender (Microsoft Malware Protection Engine) allows an unauthorized attacker to run arbitrary code by having a maliciously crafted file processed by the scanning engine. The flaw stems from an integer overflow (CWE-190) that corrupts memory during scanning, yielding full confidentiality, integrity, and availability impact. Reported by Microsoft with a vendor patch available; no public exploit identified at time of analysis.

Buffer Overflow Microsoft Integer Overflow Microsoft Malware Protection Engine
NVD VulDB
CVSS 3.1
7.8
EPSS
0.4%
CVE-2026-55011 Jul 14, 17:05 HIGH PATCH NEWS Exploit Unlikely This Week

Local code execution in Microsoft Defender's Malware Protection Engine (mpengine) arises from an integer underflow (CWE-191) that a local attacker can trigger with no prior authentication but requiring user interaction, yielding high confidentiality, integrity, and availability impact. Because Defender's scanning engine runs with SYSTEM-level privileges, successful exploitation would grant full compromise of the host. There is no public exploit identified at time of analysis and the issue is not listed in CISA KEV; Microsoft has released a fix.

Authentication Bypass Microsoft Integer Overflow Microsoft Malware Protection Engine
NVD VulDB
CVSS 3.1
7.8
EPSS
0.4%
CVE-2026-50656 Jun 16, 18:01 HIGH POC PATCH NEWS Exploit Likely This Week

Elevation of privilege in the Microsoft Malware Protection Engine (mpengine) - the scanning core shared by Microsoft Defender Antivirus - allows a low-privileged local user, tracked publicly as "RoguePlanet", to gain SYSTEM-level control by abusing how the engine resolves file links (CWE-59). Because the engine runs with the highest privileges, successful exploitation yields total loss of confidentiality, integrity, and availability. Publicly available exploit code exists (MSNightmare/RoguePlanet on GitHub) and SSVC rates technical impact as total, but there is no CISA KEV listing and EPSS is low (0.39%, 30th percentile), indicating no evidence of widespread active exploitation yet.

Microsoft Information Disclosure Microsoft Malware Protection Engine
NVD GitHub VulDB
CVSS 3.1
7.0
EPSS
0.4%
CVE-2026-45584 May 20, 13:09 HIGH POC PATCH This Week

Remote code execution in Microsoft Defender (Microsoft Malware Protection Engine) enables unauthenticated network-based attackers to corrupt heap memory and run arbitrary code on hosts running the vulnerable scanning engine. The flaw scores CVSS 8.1 with high attack complexity, affects systems by default since Defender is shipped with Windows, and at time of analysis has no public exploit identified, though Microsoft has released a vendor patch via MSRC.

Microsoft Buffer Overflow Heap Overflow Microsoft Malware Protection Engine
NVD VulDB GitHub
CVSS 3.1
8.1
EPSS
0.0%
CVE-2026-41091 May 20, 13:09 HIGH POC KEV PATCH THREAT NEWS Exploited Act Now

Local privilege escalation in Microsoft Defender (Malware Protection Engine) enables an authenticated low-privileged attacker to elevate to SYSTEM by abusing improper link resolution (CWE-59) before file access. The flaw scores CVSS 7.8 with high impact to confidentiality, integrity, and availability, and no public exploit is identified at time of analysis. Microsoft has released a patch via MSRC, and there is no current CISA KEV listing or EPSS signal indicating active mass exploitation.

Microsoft Information Disclosure Microsoft Malware Protection Engine
NVD VulDB GitHub
CVSS 3.1
7.8
EPSS
12.1%
Threat
4.9
EPSS 0% CVSS 7.8
HIGH PATCH Exploit Likely This Week

Elevation of privilege in the Microsoft Malware Protection Engine (Microsoft Defender), publicly named 'ShieldBreak', allows a locally authenticated low-privileged user to gain high-level system access. The CVSS vector confirms a local, low-complexity attack requiring only low privileges and no user interaction, with full confidentiality, integrity, and availability impact. Proof-of-concept exploit code exists (E:P in the temporal vector), and Microsoft has acknowledged the vulnerability publicly.

Microsoft Microsoft Malware Protection Engine Privilege Escalation
NVD GitHub VulDB
EPSS 0% CVSS 7.8
HIGH PATCH Exploit Unlikely This Week

Local code execution in Microsoft Defender (Microsoft Malware Protection Engine) allows an unauthorized attacker to run arbitrary code by having a maliciously crafted file processed by the scanning engine. The flaw stems from an integer overflow (CWE-190) that corrupts memory during scanning, yielding full confidentiality, integrity, and availability impact. Reported by Microsoft with a vendor patch available; no public exploit identified at time of analysis.

Buffer Overflow Microsoft Integer Overflow +1
NVD VulDB
EPSS 0% CVSS 7.8
HIGH PATCH Exploit Unlikely This Week

Local code execution in Microsoft Defender's Malware Protection Engine (mpengine) arises from an integer underflow (CWE-191) that a local attacker can trigger with no prior authentication but requiring user interaction, yielding high confidentiality, integrity, and availability impact. Because Defender's scanning engine runs with SYSTEM-level privileges, successful exploitation would grant full compromise of the host. There is no public exploit identified at time of analysis and the issue is not listed in CISA KEV; Microsoft has released a fix.

Authentication Bypass Microsoft Integer Overflow +1
NVD VulDB
EPSS 0% CVSS 7.0
HIGH POC PATCH Exploit Likely This Week

Elevation of privilege in the Microsoft Malware Protection Engine (mpengine) - the scanning core shared by Microsoft Defender Antivirus - allows a low-privileged local user, tracked publicly as "RoguePlanet", to gain SYSTEM-level control by abusing how the engine resolves file links (CWE-59). Because the engine runs with the highest privileges, successful exploitation yields total loss of confidentiality, integrity, and availability. Publicly available exploit code exists (MSNightmare/RoguePlanet on GitHub) and SSVC rates technical impact as total, but there is no CISA KEV listing and EPSS is low (0.39%, 30th percentile), indicating no evidence of widespread active exploitation yet.

Microsoft Information Disclosure Microsoft Malware Protection Engine
NVD GitHub VulDB
EPSS 0% CVSS 8.1
HIGH POC PATCH This Week

Remote code execution in Microsoft Defender (Microsoft Malware Protection Engine) enables unauthenticated network-based attackers to corrupt heap memory and run arbitrary code on hosts running the vulnerable scanning engine. The flaw scores CVSS 8.1 with high attack complexity, affects systems by default since Defender is shipped with Windows, and at time of analysis has no public exploit identified, though Microsoft has released a vendor patch via MSRC.

Microsoft Buffer Overflow Heap Overflow +1
NVD VulDB GitHub
EPSS 12% 4.9 CVSS 7.8
HIGH POC KEV PATCH THREAT Exploited Act Now

Local privilege escalation in Microsoft Defender (Malware Protection Engine) enables an authenticated low-privileged attacker to elevate to SYSTEM by abusing improper link resolution (CWE-59) before file access. The flaw scores CVSS 7.8 with high impact to confidentiality, integrity, and availability, and no public exploit is identified at time of analysis. Microsoft has released a patch via MSRC, and there is no current CISA KEV listing or EPSS signal indicating active mass exploitation.

Microsoft Information Disclosure Microsoft Malware Protection Engine
NVD VulDB GitHub

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