CVE-2018-8414: Microsoft Windows Shell Remote Code Execution Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 25 Mar 2022, 1,318 days after the CVE record was published.

How likely is exploitation in the next 30 days?

72.6%

EPSS score, percentile 99.4 of all scored records

How severe?

8.8 High

CVSS v3.1 base score, from CISA's enrichment of the record

What should I do?

CISA deadline 15 Apr 2022. Apply updates per vendor instructions.

The CVE record links no vendor advisory, patch or mitigation.

Which versions are affected?

Affected

• version 1709 (Server Core Installation)
• version 1803 (Server Core Installation)
• Version 1703 for 32-bit Systems
• Version 1703 for x64-based Systems
• Version 1709 for 32-bit Systems
• Version 1709 for x64-based Systems

and 2 more in the table below

Versions by product

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

What to do

CISA due date for this action: 15 April 2022.

Advisories and patches

The CVE record links no vendor advisory, patch or mitigation.

Linked from CISA's catalog entry

• https://nvd.nist.gov/vuln/detail/CVE-2018-8414

Affected products and versions

As listed in the CVE record.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

About this vulnerability

A remote code execution vulnerability exists when the Windows Shell does not properly validate file paths.

Summary: CISA's KEV catalog, as of 28 Oct 2026.

• CISA added CVE-2018-8414 to its Known Exploited Vulnerabilities (KEV) catalog on 25 Mar 2022.
• CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
• The due date CISA sets for the required action is 15 Apr 2022.
• The CVE record was published on 15 Aug 2018, 1,318 days before it was added to KEV.
• The CVE record carries a CVSS v3.1 base score of 8.8 (High), taken from CISA's enrichment of the record.
• FIRST's EPSS model puts the probability of exploitation in the next 30 days at 72.6% (percentile 99.4), as of 28 Oct 2026.
• CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.

Description

A remote code execution vulnerability exists when the Windows Shell does not properly validate file paths, aka "Windows Shell Remote Code Execution Vulnerability." This affects Windows 10 Servers, Windows 10.

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.

Weakness

• CWE-20: Improper Input Validation

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

References

• 105016 (Vulnerability database)
• 1041458 (Vulnerability database)
• portal.msrc.microsoft.com

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