CVE-2020-0901Network attack vector

Code execution via mishandled in-memory objects

Published May 21, 2020 · Updated Aug 19, 2026

Memory corruption in Microsoft Excel allows context-dependent attackers to execute code as the current user through a crafted workbook. Excel mishandles objects in memory while processing the file, but Microsoft has not disclosed the specific object type or invalid memory operation. Exploitation requires a user to open the crafted file, and resulting code inherits that user's privileges, including administrative rights when present.

CVSS severity9.8
Critical
EPSS probability4.31%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Memory corruption in Microsoft Excel allows context-dependent attackers to execute code as the current user through a crafted workbook. Excel mishandles objects in memory while processing the file, but Microsoft has not disclosed the specific object type or invalid memory operation. Exploitation requires a user to open the crafted file, and resulting code inherits that user's privileges, including administrative rights when present.

The record

CVE
CVE-2020-0901
Published
May 21, 2020
Updated
Aug 19, 2026
Vendor
Microsoft
Product
Microsoft Office 2019
Classifications
T1203, T1204.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 21, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 19, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=19.0.0 <https://aka.ms/OfficeSecurityReleases

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office 2019version=19.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Excel 2016version=16.0.0.0 <publication
Microsoft · Microsoft Excel 2010version=13.0.0.0 <publication
Microsoft · Microsoft Office 2016 for Macversion=16.0.0 <publication
Microsoft · Microsoft Excel 2013version=15.0.0.0 <publication
Microsoft · Microsoft Office 2019 for Macversion=16.0.0 <publication
Microsoft · Microsoft 365 Apps for enterpriseversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

Published CVSS scores

7.5NVDAV:N/AC:L/Au:N/C:P/I:P/A:P
9.8NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1203Exploitation for Client Execution
T1204.002Malicious File

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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