dbcve.org
365 AppsApplication · Microsoft

CVE-2025-53735

HIGH · 7.8 CVSS v3.1 Published 2025-08-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
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
Use after free 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 · high confidence

A use-after-free vulnerability in Microsoft Office Excel allows an attacker to execute arbitrary code locally by exploiting improper memory handling after a memory pointer is freed. The vulnerability can be triggered by opening a specially crafted malicious Excel file.

MitigationApply the Microsoft security update for CVE-2025-53735 when available. Until then, enable Protected View for files from untrusted sources and avoid opening suspicious Excel 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
ExcelApplication
Affected:= 2016
OfficeApplication
Affected:= 2019
Office Long Term Servicing ChannelApplication
Affected:= 2021= 2024
Office Online ServerApplication
Affected:all versions

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. Verify Microsoft Excel is installed
    Check for Excel executable at common installation paths (C:\Program Files\Microsoft Office\root\Office16\EXCEL.EXE or C:\Program Files (x86)\Microsoft Office\root\Office16\EXCEL.EXE) or search for Excel.exe using Get-ChildItem -Recurse -Filter Excel.exe in PowerShell
    Affected if Excel.exe is not found on the system - the system is not affected because Excel is not installed
  2. Determine installed Excel version from registry
    Query the registry key HKLM\SOFTWARE\Microsoft\Office\ClickToRun\Configuration (for Microsoft 365/Office 365) or HKLM\SOFTWARE\Microsoft\Office\{version}\Excel\InstallRoot (for standalone Office) using PowerShell: Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Office\ClickToRun\Configuration' | Select-Object Platform,VersionToReport
    Affected if VersionToReport or platform value indicates Microsoft 365 Apps (all versions are affected)
  3. Get Excel version from application
    Open Excel, go to File > Account > About Excel, or run Excel and execute: (New-Object -COMObject Excel.Application).Version in PowerShell to retrieve the exact version number
    Affected if Version matches 2016, 2019, 2021, or 2024 (or falls within the affected ranges specified in the CVE)
  4. Check for Microsoft Office Long Term Servicing Channel
    Query registry HKLM\SOFTWARE\Microsoft\Office\LTSC\Configuration or check if the installation is an LTSC version by examining the Office installation source and version details via: Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Office\ClickToRun\Configuration' | Select-Object UpdateChannel
    Affected if UpdateChannel indicates Long Term Servicing Channel installation with version 2021 or 2024
  5. Check for Microsoft Office Online Server
    If this is a server environment, verify if Office Online Server is installed by checking for the service: Get-Service -Name 'WACSM' -ErrorAction SilentlyContinue or checking IIS for Office Online applications
    Affected if Office Online Server is detected - all versions are affected per the CVE

The environment is affected if any version of Microsoft Excel, Microsoft Office, or Microsoft Office Online Server matching the CVE-specified versions (2016, 2019, 2021, 2024, or Microsoft 365 Apps) is installed, since the vulnerability triggers simply by opening a malicious Excel file.

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-2025-53735 when available. Until then, enable Protected View for files from untrusted sources and avoid opening suspicious Excel attachments.

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 help mitigating

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

Free · runs locally
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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-2025-53735 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