CVE-2020-0991

Code execution via improper in-memory object handling

Published Apr 15, 2020 · Updated Aug 4, 2024

Remote code execution in affected Microsoft Office and Office 365 ProPlus releases allows remote attackers to run code through a crafted file. Microsoft states that Office mishandles objects in memory but has not disclosed the affected parser, object type, or invalid memory operation. Exploitation requires a user to open the file in an affected Office application; the Preview Pane does not trigger the flaw, and code runs with the user's rights.

CVSS severity7.8
High
EPSS probability11.83%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in affected Microsoft Office and Office 365 ProPlus releases allows remote attackers to run code through a crafted file. Microsoft states that Office mishandles objects in memory but has not disclosed the affected parser, object type, or invalid memory operation. Exploitation requires a user to open the file in an affected Office application; the Preview Pane does not trigger the flaw, and code runs with the user's rights.

The record

CVE
CVE-2020-0991
Published
Apr 15, 2020
Updated
Aug 4, 2024
Vendor
Microsoft
Product
Microsoft Office
Classifications
T1204.002, T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=2010 Service Pack 2 (32-bit editions)
  2. Affected versionversion=2010 Service Pack 2 (64-bit editions)
  3. Affected versionversion=2013 RT Service Pack 1
  4. Affected versionversion=2013 Service Pack 1 (32-bit editions)
  5. Affected versionversion=2013 Service Pack 1 (64-bit editions)
  6. Affected versionversion=2016 (32-bit edition)
  7. Affected versionversion=2016 (64-bit edition)
  8. Affected versionversion=2019 for 32-bit editions
  9. Affected versionversion=2019 for 64-bit editions

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Officeversion=2010 Service Pack 2 (32-bit editions); version=2010 Service Pack 2 (64-bit editions); version=2013 RT Service Pack 1; version=2013 Service Pack 1 (32-bit editions); version=2013 Service Pack 1 (64-bit editions); version=2016 (32-bit edition); version=2016 (64-bit edition); version=2019 for 32-bit editions; version=2019 for 64-bit editions
Microsoft · Microsoft 365 Apps for enterpriseversion=32-bit Systems; version=64-bit Systems

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
9.3NIST NVDAV:N/AC:M/Au:N/C:C/I:C/A:C

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1204.002Malicious File
T1203Exploitation for Client Execution

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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