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365 AppsApplication · Microsoft

CVE-2025-62556

HIGH · 7.8 CVSS v3.1 Published 2025-12-09
Fix available
A fix is available. Upgrade to 16.0.10417.20075 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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
Untrusted pointer dereference in Microsoft Office Excel allows an unauthorized 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

This is an untrusted pointer dereference vulnerability in Microsoft Office Excel where the software fails to properly validate a pointer before using it, allowing an attacker to manipulate memory and achieve arbitrary code execution locally without authentication.

MitigationApply the latest Microsoft Office security updates for Excel as soon as they become available, and ensure endpoint protection and application control policies are in place to limit the impact of potential local code execution.

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
ExcelApplication
Affected:= 2016
OfficeApplication
Affected:= 2019
Office Long Term Servicing ChannelApplication
Affected:= 2021= 2024
Office Online ServerApplication
Affected:< 16.0.10417.20075

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
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:N/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. Confirm Excel is installed
    Open Excel and go to File > Account > About Excel, or check Programs and Features for Microsoft Excel in the installed programs list
    Affected if Excel is not installed on the system, the system is not affected by this specific Excel vulnerability
  2. Identify the installed Excel version number
    In Excel, go to File > Account > About Excel to see the version (for example, 16.0.xxxxx.xxxxx). For command-line inspection, run: powershell "(Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Office\ClickToRun\Configuration' -ErrorAction SilentlyContinue).ProductReleaseIDs" or check registry key HKLM\SOFTWARE\Microsoft\Office\ClickToRun\Configuration
    Affected if The installed version falls within the affected ranges: Excel 2016 and later, Office 2019 and later, Office LTSC 2021 and later, or Office Online Server versions below 16.0.10417.20075
  3. For Office 365/ Microsoft 365 Apps, verify the update channel version
    Run: powershell "Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Office\ClickToRun\Configuration' | Select-Object ProductReleaseIDs, VersionToReport" to see the current update channel and version
    Affected if All Microsoft 365 Apps channels are listed as affected, meaning any Microsoft 365 Excel installation is potentially vulnerable
  4. For Office Online Server, check the specific build number
    Check the installed version of Office Online Server by reviewing the installed programs or using: Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Office\Server\16.0\Build'
    Affected if Office Online Server version is lower than 16.0.10417.20075

A system is affected if Microsoft Excel or Microsoft Office with Excel is installed and the version falls within the stated ranges (Excel >=2016, Office >=2019, Office LTSC >=2021, Office Online Server <16.0.10417.20075, or any Microsoft 365 Apps version).

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.

dbcve · scoped
Upgrade available Upgrade to 16.0.10417.20075 or later
Fixed in 16.0.10417.20075
Interim mitigation

Apply the latest Microsoft Office security updates for Excel as soon as they become available, and ensure endpoint protection and application control policies are in place to limit the impact of potential local code execution.

Recommended fix Moderate confidence

Apply Microsoft security updates for CVE-2025-62556; for Office Online Server upgrade to >= 16.0.10417.20075

  1. Open Microsoft Excel or any affected Office application
  2. Go to File > Account > Update Options
  3. Select 'Update Now' to download and install the latest security updates from Microsoft Update
  4. Alternatively, navigate to Microsoft Update Catalog (update.microsoft.com) and search for CVE-2025-62556 security updates
  5. For Office Online Server, ensure the server is updated to version 16.0.10417.20075 or later
Caveat Standard Office security update with no expected breaking changes

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in 365 Apps Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,560.

Scan for this in your stack

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dbcve dependency scanner

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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-2025-62556 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