CVE-2026-55047
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 · uneditedOut-of-bounds read in Microsoft Office allows an unauthorized attacker to disclose information locally.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- Weekly Recap: Proxy Botnets, Browser Ransomware, AI Agent ...
- Microsoft CVE Summary - Bleeping Computer
Surfaced from public web coverage — external links open in a new tab.
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 confidenceThis is an out-of-bounds read vulnerability in Microsoft Office where the application reads memory beyond allocated buffer boundaries. The flaw allows a local attacker to potentially access sensitive information from the application's memory space through specially crafted Office documents or files.
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 versions< 16.0.10417.20175< 16.0.19725.20434= 16.0.19725.20434= 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
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
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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Identify installed Microsoft Office or Microsoft 365 versionOpen any Office application (Word, Excel, PowerPoint), go to File > Account, and look for the version/build number under 'About [App]'. Alternatively, run 'winver' command or check Programs and Features for Microsoft Office or Microsoft 365 Apps.Affected if The installed version matches one of the affected products: Microsoft 365 Apps, Microsoft 365, Office 2019, Office 2021, or Office 2024 - all versions of these products are affected.
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Identify SharePoint Server version if installedCheck SharePoint Administration Center > System Settings > Manage servers in this farm, or run 'Get-SPFarm | Select BuildVersion' in SharePoint Management Shell. Also check Programs and Features for Microsoft SharePoint Server 2016 or 2019.Affected if SharePoint Server 2016 or 2019 is installed, or version equals 16.0.19725.20434, or version is lower than 16.0.19725.20434.
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Identify Office Online Server version if installedCheck Programs and Features for Microsoft Office Online Server, or run 'Get-OfficeWebAppsFarm' in PowerShell on the server to see the build version.Affected if Office Online Server version is installed and is lower than 16.0.10417.20175.
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Verify if the security update has been appliedCheck Windows Update history or the Office Update History page (https://docs.microsoft.com/officeupdates/update-history-office) for recent security patches related to this CVE. In Office apps, File > Account > Update Options > Update Now will show if updates are available.Affected if No security update addressing CVE-2026-55047 has been installed - the product remains affected.
A system is affected if any Microsoft Office product (Office 2019/2021/2024, Microsoft 365 Apps, SharePoint Server 2016/2019, or Office Online Server) from the affected version ranges is installed without the corresponding security patch applied.
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 data16.0.10417.2017516.0.19725.20434
Apply available Microsoft Office security updates when released. Until a patch is available, exercise caution with untrusted Office documents and consider restricting local user access to sensitive data.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-55047 — 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-2026-55047 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