CVE-2021-38658

Remote code execution via crafted graphics file

Published Sep 15, 2021 · Updated Aug 10, 2026

Remote code execution in Microsoft Office 2013, 2016, and 2019 allows remote attackers to execute code when a user opens a crafted document. The flaw resides in Office graphics processing, but Microsoft has not published the specific parsing operation or memory-safety failure that permits control of execution. User interaction is required, and the documented impact is execution with the privileges of the Office process; no network-service attack path is described.

CVSS severity7.8
High
EPSS probability6.31%
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 Microsoft Office 2013, 2016, and 2019 allows remote attackers to execute code when a user opens a crafted document. The flaw resides in Office graphics processing, but Microsoft has not published the specific parsing operation or memory-safety failure that permits control of execution. User interaction is required, and the documented impact is execution with the privileges of the Office process; no network-service attack path is described.

The record

CVE
CVE-2021-38658
Published
Sep 15, 2021
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Microsoft Office 2016
Classifications
T1203
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 15, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 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=16.0.0 <5215.1000

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office 2016version=16.0.0 <5215.1000
Microsoft · Microsoft Office 2019version=19.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office 2013version=15.0.0 <5381.1000

Published CVSS scores

7.8Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:R/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 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

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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