CVE-2021-38660

Code execution after user interaction

Published Sep 15, 2021 · Updated Aug 10, 2026

Remote code execution in Microsoft Excel 2013 SP1 before 5381.1000 allows attackers to execute code after user interaction. Microsoft identifies the affected locus only as Office Graphics and has not published the input format, parser, or incorrect operation responsible. Exploitation requires a user to process attacker-controlled graphics content, after which code executes in the user's application context.

CVSS severity7.8
High
EPSS probability2.27%
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 Excel 2013 SP1 before 5381.1000 allows attackers to execute code after user interaction. Microsoft identifies the affected locus only as Office Graphics and has not published the input format, parser, or incorrect operation responsible. Exploitation requires a user to process attacker-controlled graphics content, after which code executes in the user's application context.

The record

CVE
CVE-2021-38660
Published
Sep 15, 2021
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Microsoft Excel 2013
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=15.0.0.0 <5381.1000

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Excel 2013version=15.0.0.0 <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
6.8NIST NVDAV:N/AC:M/Au:N/C:P/I:P/A:P

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.

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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.

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Technologies

Your stack

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Your stack

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