CVE-2024-38021Network attack vector

Remote code execution via Protected View bypass

Published Jul 9, 2024 · Updated Feb 10, 2026

Improper input validation in Microsoft Outlook in affected Office releases allows remote attackers to execute code through a crafted link. Outlook insufficiently validates the link before applying the Protected View protocol, allowing the crafted content to bypass that protection. Opening content from an untrusted sender is required, while content from a trusted sender can trigger execution without another interaction.

CVSS severityUnavailable
Unscored
EPSS probability3.50%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Microsoft Outlook in affected Office releases allows remote attackers to execute code through a crafted link. Outlook insufficiently validates the link before applying the Protected View protocol, allowing the crafted content to bypass that protection. Opening content from an untrusted sender is required, while content from a trusted sender can trigger execution without another interaction.

The record

CVE
CVE-2024-38021
Published
Jul 9, 2024
Updated
Feb 10, 2026
Vendor
Microsoft
Product
Microsoft Office 2016
Classifications
CWE-20, T1204.001, T1203
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 9, 2024CVE publishedPublication date reported by the CVE source.
  2. Feb 10, 2026Record 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=16.0.0 <16.0.5456.1000

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Microsoft · Microsoft Office 2016version=16.0.0 <16.0.5456.1000
Microsoft · Microsoft Office 2019version=19.0.0 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft Office LTSC 2021version=16.0.1 <https://aka.ms/OfficeSecurityReleases
Microsoft · Microsoft 365 Apps for enterpriseversion=16.0.1 <https://aka.ms/OfficeSecurityReleases

Published CVSS scores

8.8Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC: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)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1204.001Malicious Link
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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