CVE-2026-45456
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 · uneditedAccess of resource using incompatible type ('type confusion') 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 confidenceType confusion vulnerability in Microsoft Office allows an unauthorized attacker to execute code locally. The vulnerability stems from the software accessing a resource using an incompatible type, leading to undefined behavior that can be exploited for 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 dataall versionsall versionsall versionsall versionsall versionsall versions< 16.0.19725.20384= 2016= 2019CVSS 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
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/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 checksWork through these to decide whether this CVE applies to you.
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Verify Office installationOpen File Explorer, navigate to C:\Program Files\Microsoft Office or C:\Program Files (x86)\Microsoft Office, or check Programs and Features in Control Panel for Microsoft Office entriesAffected if Any Microsoft Office application (Word, Excel, PowerPoint, Outlook, etc.) is listed as installed
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Identify installed Office versionOpen any Office app (e.g., Word), go to File > Account, and note the version under 'About [app]'; alternatively, run 'winword /?' or 'excel /?' from Command Prompt to see version infoAffected if The version shown corresponds to Office 2016, 2019, 2021, 2024, or Microsoft 365 Apps (all versions of these products are affected)
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Check for Microsoft 365 subscription statusOpen any Office app, go to File > Account, and look for 'Microsoft 365' under subscription information; or check if the device is licensed for Microsoft 365Affected if The system has an active Microsoft 365 subscription (all Microsoft 365 versions are affected)
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Verify SharePoint Server version if applicableOpen SharePoint Administration Center, go to System Settings > Manage servers in this farm, or run 'Get-SPFarm | Select BuildVersion' in SharePoint Management ShellAffected if SharePoint Server 2016, 2019, or a version earlier than build 16.0.19725.20384 is installed
If any of the affected Office products (Office 2016/2019/2021/2024, Microsoft 365 Apps, or Microsoft 365) or vulnerable SharePoint versions are installed, the environment is affected by this vulnerability.
Generated from the published advisory. Verify against your own configuration.
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 data16.0.19725.20384
Apply Microsoft Office security updates promptly. Verify that Microsoft Office is running supported, patched versions. Restrict local user privileges where feasible to limit impact of local code execution vulnerabilities.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-45456 — 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 sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-45456 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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