365 AppsApplication · Microsoft

CVE-2026-45643

HIGH · 7.8 CVSS v3.1 Published 2026-06-09
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
Untrusted pointer dereference in Microsoft Office Word 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

Untrusted pointer dereference vulnerability in Microsoft Office Word enables an unauthenticated attacker to execute arbitrary code locally on the target system. The vulnerability stems from improper validation of pointers when processing specially crafted Word documents, allowing memory corruption that can be leveraged for code execution.

MitigationApply Microsoft security updates for Office Word as they become available. Verify patch deployment across all affected endpoints and test Office functionality post-update.

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 2021Application
Affected:all versions
Office 2024Application
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 Word installation
    Locate WINWORD.exe on the system - typically found in C:\Program Files\Microsoft Office\root\Office## or C:\Program Files (x86)\Microsoft Office\root\Office## where ## is the version number (16, 19, etc.)
    Affected if WINWORD.exe exists on the system, indicating Office Word is installed
  2. Obtain installed Word version
    Right-click WINWORD.exe, select Properties, then view the Details tab for Product Version, or run 'winword.exe /?' from Command Prompt to display version information
    Affected if The installed version matches any Microsoft Office 2021, 2024, or Microsoft 365/365 Apps release
  3. Confirm patch status
    Open Windows Settings > Windows Update > Update History and search for KB entries related to this CVE, or use the Microsoft Update Catalog to check if the security update for CVE-2026-45643 has been installed
    Affected if The security update addressing CVE-2026-45643 is NOT listed in installed updates, meaning the vulnerability remains unpatched

If Microsoft Office Word is installed and the specific security update for CVE-2026-45643 has not been applied, the environment is vulnerable to untrusted pointer dereference and potential code execution.

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 Microsoft security updates for Office Word as they become available. Verify patch deployment across all affected endpoints and test Office functionality post-update.

Fix this in 365 Apps Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2026-45643 — 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-2026-45643 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