365 AppsApplication · Microsoft

CVE-2026-45475

HIGH · 7.8 CVSS v3.1 Published 2026-06-09
Fix available
A fix is available. Upgrade to 16.0.19725.20384 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
Heap-based buffer overflow in Microsoft Office 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 a heap-based buffer overflow vulnerability in Microsoft Office that allows an unauthorized local attacker to execute arbitrary code. The flaw exists in how Microsoft Office handles specific data structures in memory, enabling an attacker to overwrite heap metadata and redirect execution flow.

MitigationApply Microsoft security updates immediately upon release. Until a patch is available, restrict local user privileges and avoid opening untrusted Office documents from unknown sources.

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
Microsoft 365Application
Affected:all versions
Office 2016Application
Affected:all versions
Office 2019Application
Affected:all versions
Office 2021Application
Affected:all versions
Office 2024Application
Affected:all versions
Sharepoint ServerApplication
Affected:< 16.0.19725.20384= 2016= 2019

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. Identify installed Microsoft Office product
    Open any Office application (Word, Excel, etc.), go to File > Account > About [App] to see the version number (e.g., 16.0.xxxx.xxxx), or check Add/Remove Programs for installed Microsoft Office products
    Affected if Any Microsoft Office product listed in affected products is installed (2016, 2019, 2021, 2024, or Microsoft 365 Apps)
  2. Confirm Office version matches affected range
    Compare the installed version number to the affected ranges. Office versions are typically 16.0.xxxx.xxxx (Office 2016-2024) or click-to-run versions for Microsoft 365. If the version starts with 16.0 and falls within the installed product line, it is affected
    Affected if The installed version is any version of Office 2016, 2019, 2021, 2024, or Microsoft 365 Apps since all versions of these products are affected per the CVE
  3. Check for SharePoint Server installation
    On the server, open SharePoint Management Shell and run: (Get-SPFarm).BuildVersion or check registry HKLM\SOFTWARE\Microsoft\Office Server\16.0\Setup\ProductVersion to identify the SharePoint version
    Affected if SharePoint Server 2016, 2019, or any version earlier than 16.0.19725.20384 is installed
  4. Verify the specific SharePoint version number
    If SharePoint is installed, note the full build version (for example, 16.0.19725.20384 or 16.0.14701.20008). Compare against the CVE threshold of 16.0.19725.20384
    Affected if SharePoint build is less than 16.0.19725.20384, or equals 2016 or 2019 (specific build numbers for these releases)

You are affected if any Microsoft Office product (2016, 2019, 2021, 2024, or Microsoft 365 Apps) or SharePoint Server (2016, 2019, or build below 16.0.19725.20384) is installed on your system.

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
Upgrade available Upgrade to 16.0.19725.20384 or later
Fixed in 16.0.19725.20384
Interim mitigation

Apply Microsoft security updates immediately upon release. Until a patch is available, restrict local user privileges and avoid opening untrusted Office documents from unknown sources.

Fix this in 365 Apps Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-45475 — 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-2026-45475 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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