How severe is CVE-2020-1240?

CVE-2020-1240 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-1240 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 14% (96th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-1240?

CVE-2020-1240 affects Microsoft 365 Apps. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-1240?

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-2020-1240 published?

CVE-2020-1240 was published on 2020-07-14 and last updated on 2026-06-17.

CVE-2020-1240

CVE-2020-1240 is a high-severity vulnerability in Microsoft 365 Apps with a CVSS 3.x base score of 8.8. Its EPSS exploit-prediction score of 14% places it in the 96th percentile, indicating an elevated likelihood of exploitation.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.3
EPSS exploit prediction: 14% (96th percentile)
Actively exploited: Not listed in CISA KEV
Affected product: Microsoft 365 Apps
Published: 2020-07-14
Last modified: 2026-06-17

Description

A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle objects in memory, aka 'Microsoft Excel Remote Code Execution Vulnerability'.

Frequently asked questions

What is CVE-2020-1240?: A remote code execution vulnerability exists in Microsoft Excel software when the software fails to properly handle objects in memory, aka 'Microsoft Excel Remote Code Execution Vulnerability'.
How severe is CVE-2020-1240?: CVE-2020-1240 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-1240 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 14% (96th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-1240?: CVE-2020-1240 affects Microsoft 365 Apps. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-1240?: 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-2020-1240 published?: CVE-2020-1240 was published on 2020-07-14 and last updated on 2026-06-17.

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1240

Affected products (1)

cpe:2.3:a:microsoft:365_apps:-:*:*:*:enterprise:*:*:*

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