365 AppsApplication · Microsoft

CVE-2025-47171

MEDIUM · 6.7 CVSS v3.1 Published 2025-06-10
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
67/100
Remediation priority · Elevated

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Improper input validation in Microsoft Office Outlook allows an authorized attacker to execute code locally.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

Improper input validation vulnerability in Microsoft Office Outlook allows an authorized attacker to execute code locally on the affected system. The vulnerability stems from insufficient input validation within the Outlook application, enabling local code execution with the privileges of the authenticated user.

MitigationApply the Microsoft security update for CVE-2025-47171 to Microsoft Office Outlook installations; as an interim measure, restrict user permissions and exercise caution with untrusted email attachments.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
365 AppsApplication
Affected:all versions
OfficeApplication
Affected:= 2019
Office Long Term Servicing ChannelApplication
Affected:= 2021= 2024
OutlookApplication
Affected:= 2016

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Local
Complexity
High
Privileges
Low
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Verify Microsoft Outlook is installed
    Check for Outlook.exe in typical installation paths such as C:\Program Files\Microsoft Office\root\Office16\ or C:\Program Files (x86)\Microsoft Office\root\Office16\, or query the Windows Registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\OUTLOOK.EXE
    Affected if Outlook.exe is found on the system
  2. Determine the installed Outlook version
    Open Outlook, go to File > Office Account > About Outlook, or check the version in the registry at HKLM\SOFTWARE\Microsoft\Office\ClickToRun\Configuration or HKLM\SOFTWARE\Microsoft\Office\16.0\Common\InstallRoot (path varies by version and installation type)
    Affected if The displayed version matches one of the affected versions: Microsoft 365 Apps (any version), Office 2019, Office LTSC 2021, Office LTSC 2024, or Outlook 2016
  3. Check for installed security updates
    Open Windows Update > View update history, or check the installed updates list for a security update with knowledge base article ID related to CVE-2025-47171 (check Microsoft Security Response Center for the specific KB number)
    Affected if No corresponding security update for CVE-2025-47171 is listed as installed
  4. Confirm the Outlook component is vulnerable
    The vulnerability affects the Outlook application itself through improper input validation. If Outlook is installed and the version matches an affected release without the security patch, the component is present and the flaw can potentially be triggered during normal Outlook operation
    Affected if Outlook is running an affected version without the CVE-2025-47171 security patch applied

The environment is affected if Microsoft Outlook is installed with version 2016, 2019, 2021, 2024, or any Microsoft 365 Apps version, and the CVE-2025-47171 security update has not been installed.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Microsoft security update for CVE-2025-47171 to Microsoft Office Outlook installations; as an interim measure, restrict user permissions and exercise caution with untrusted email attachments.

Fix this in 365 Apps Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2025-47171 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-47171 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data