How severe is CVE-2018-0866?

CVE-2018-0866 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2018-0866 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 44% (99th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2018-0866?

CVE-2018-0866 primarily affects Microsoft Internet Explorer. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2018-0866?

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-2018-0866 published?

CVE-2018-0866 was published on 2018-02-15 and last updated on 2026-06-17.

CVE-2018-0866

CVE-2018-0866 is a high-severity vulnerability in Microsoft Internet Explorer with a CVSS 3.x base score of 7.5. Its EPSS exploit-prediction score of 44% places it in the 99th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-787.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 9.3
EPSS exploit prediction: 44% (99th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-787
Affected product: Microsoft Internet Explorer
Published: 2018-02-15
Last modified: 2026-06-17

Description

Internet Explorer in Microsoft Windows 7 SP1, Windows Server 2008 and R2 SP1, Windows 8.1 and Windows RT 8.1, Windows Server 2012 and R2, Windows 10 Gold, 1511, 1607, 1703, 1709, and Windows Server 2016 allows remote code execution, due to how the scripting engine handles objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2018-0834, CVE-2018-0835, CVE-2018-0836, CVE-2018-0837, CVE-2018-0838, CVE-2018-0840, CVE-2018-0856, CVE-2018-0857, CVE-2018-0858, CVE-2018-0859, CVE-2018-0860, and CVE-2018-0861.

Frequently asked questions

What is CVE-2018-0866?: Internet Explorer in Microsoft Windows 7 SP1, Windows Server 2008 and R2 SP1, Windows 8.1 and Windows RT 8.1, Windows Server 2012 and R2, Windows 10 Gold, 1511, 1607, 1703, 1709, and Windows Server 2016 allows remote code execution, due to how the scripting engine handles objects in memory, aka "Scripting Engine Memory Corruption Vulnerability". This CVE ID is unique from CVE-2018-0834, CVE-2018-0835, CVE-2018-0836, CVE-2018-0837, CVE-2018-0838, CVE-2018-0840, CVE-2018-0856, CVE-2018-0857, CVE-2018-0858, CVE-2018-0859, CVE-2018-0860, and CVE-2018-0861.
How severe is CVE-2018-0866?: CVE-2018-0866 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2018-0866 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 44% (99th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2018-0866?: CVE-2018-0866 primarily affects Microsoft Internet Explorer. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2018-0866?: 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-2018-0866 published?: CVE-2018-0866 was published on 2018-02-15 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:microsoft:internet_explorer:11:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:internet_explorer:10:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:internet_explorer:9:*:*:*:*:*:*:*

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