How severe is CVE-2017-11940?

CVE-2017-11940 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2017-11940 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2017-11940?

CVE-2017-11940 affects Microsoft Malware Protection Engine. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2017-11940?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2017-11940 published?

CVE-2017-11940 was published on 2017-12-08 and last updated on 2026-06-17.

CVE-2017-11940

CVE-2017-11940 is a high-severity vulnerability in Microsoft Malware Protection Engine with a CVSS 3.x base score of 7.8. Its EPSS exploit-prediction score of 20% places it in the 97th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-119.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 9.3
EPSS exploit prediction: 20% (97th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-119
Affected product: Microsoft Malware Protection Engine
Published: 2017-12-08
Last modified: 2026-06-17

Description

The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on Windows 7 SP1, Windows 8.1, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, 1709 and Windows Server 2016, Windows Server, version 1709, Microsoft Exchange Server 2013 and 2016, does not properly scan a specially crafted file leading to remote code execution. aka "Microsoft Malware Protection Engine Remote Code Execution Vulnerability". This is different than CVE-2017-11937.

Frequently asked questions

What is CVE-2017-11940?: The Microsoft Malware Protection Engine running on Microsoft Forefront and Microsoft Defender on Windows 7 SP1, Windows 8.1, Windows RT 8.1, Windows 10 Gold, 1511, 1607, and 1703, 1709 and Windows Server 2016, Windows Server, version 1709, Microsoft Exchange Server 2013 and 2016, does not properly scan a specially crafted file leading to remote code execution. aka "Microsoft Malware Protection Engine Remote Code Execution Vulnerability". This is different than CVE-2017-11937.
How severe is CVE-2017-11940?: CVE-2017-11940 has a CVSS 3.x base score of 7.8, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2017-11940 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 20% (97th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2017-11940?: CVE-2017-11940 affects Microsoft Malware Protection Engine. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2017-11940?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2017-11940 published?: CVE-2017-11940 was published on 2017-12-08 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:microsoft:malware_protection_engine:*:*:*:*:*:*:*:*

More vulnerabilities in Microsoft Malware Protection Engine

CVE-2013-1346 — Critical (CVSS 9.3): mpengine.dll in Microsoft Malware Protection Engine before 1.1.9506.0 on x64 platforms allows remote attackers to…
CVE-2006-5270 — Critical (CVSS 9.3): Integer overflow in the Microsoft Malware Protection Engine (mpengine.dll), as used by Windows Live OneCare, Antigen,…
CVE-2026-45584 — High (CVSS 8.1): Heap-based buffer overflow in Microsoft Defender allows an unauthorized attacker to execute code over a network.
CVE-2026-50656 — High (CVSS 7.8): Microsoft is aware of an elevation of privilege in the Microsoft Malware Protection Engine in Microsoft Defender…
CVE-2026-41091 — High (CVSS 7.8): Improper link resolution before file access ('link following') in Microsoft Defender allows an authorized attacker to…
CVE-2021-42298 — High (CVSS 7.8): Microsoft Defender Remote Code Execution Vulnerability

All CVEs affecting Microsoft Malware Protection Engine →

Other CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities

CVE-2026-2778 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the DOM: Core & HTML component. This vulnerability was fixed in…
CVE-2026-2776 — Critical (CVSS 10.0): Sandbox escape due to incorrect boundary conditions in the Telemetry component in External Software. This vulnerability…
CVE-2025-1866 — Critical (CVSS 10.0): Improper Restriction of Operations within the Bounds of a Memory Buffer vulnerability in warmcat libwebsockets allows…
CVE-2022-27625 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
CVE-2022-27624 — Critical (CVSS 10.0): A vulnerability regarding improper restriction of operations within the bounds of a memory buffer is found in the…
CVE-2020-11896 — Critical (CVSS 10.0): The Treck TCP/IP stack before 6.0.1.66 allows Remote Code Execution, related to IPv4 tunneling.

Browse all CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer) vulnerabilities →