How severe is CVE-2020-17066?

CVE-2020-17066 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-2020-17066 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-17066?

CVE-2020-17066 affects Microsoft Excel. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-17066?

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-2020-17066 published?

CVE-2020-17066 was published on 2020-11-11 and last updated on 2026-06-17.

CVE-2020-17066

CVE-2020-17066 is a high-severity vulnerability in Microsoft Excel with a CVSS 3.x base score of 7.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.

Key facts

Severity: High (CVSS 3.x base score 7.8)
CVSS v2: 9.3
EPSS exploit prediction: 4% (89th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft Excel
Published: 2020-11-11
Last modified: 2026-06-17

Description

Microsoft Excel Remote Code Execution Vulnerability

Frequently asked questions

What is CVE-2020-17066?: Microsoft Excel Remote Code Execution Vulnerability
How severe is CVE-2020-17066?: CVE-2020-17066 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-2020-17066 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-17066?: CVE-2020-17066 affects Microsoft Excel. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-17066?: 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-2020-17066 published?: CVE-2020-17066 was published on 2020-11-11 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-17066

Affected products (1)

cpe:2.3:a:microsoft:excel:2010:sp2:*:*:*:*:*:*

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