CVE-2026-47639
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 · uneditedImproper neutralization of input during web page generation ('cross-site scripting') in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network.
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 a cross-site scripting (XSS) vulnerability in Microsoft Office SharePoint where improper input neutralization allows attackers to inject malicious scripts into web pages. The vulnerability enables spoofing attacks, likely through injecting malicious content that appears to originate from the legitimate SharePoint site.
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< 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
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/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 SharePoint Server versionOpen SharePoint Management Shell and run: Get-SPFarm | Select-Object BuildVersionAffected if Version is below 16.0.19725.20384 OR version matches SharePoint Server 2016 or 2019 build patterns (16.0.xxxx) without the cumulative update applied
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Confirm SharePoint edition and buildIn SharePoint Central Administration, go to 'System Settings' > 'Manage farms' or run 'Get-SPFarm' in Management Shell to view the exact build number and patch levelAffected if Build number is lower than 16.0.19725.20384
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Check for recent security updatesOpen Windows Server Update Services (WSUS) or check 'Control Panel' > 'Programs' > 'View installed updates' for any Microsoft SharePoint security updates installed after the CVE publication dateAffected if No corresponding security update for CVE-2026-47639 is installed
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Verify SharePoint web applications are accessibleAccess Central Administration and confirm at least one SharePoint web application is published and accessible to usersAffected if SharePoint web applications exist and are active, making the XSS vulnerability exploitable in user-facing pages
Your environment is affected if you run any version of SharePoint Server 2016 or 2019, or any build prior to 16.0.19725.20384, and you have active web applications that accept user input.
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.
dbcve · scoped16.0.19725.20384
Implement proper input validation and output encoding for all user-supplied data in SharePoint pages. Additionally, configure Content Security Policy (CSP) headers to restrict script execution and validate affected SharePoint components for existing XSS payloads.
SharePoint Server build 16.0.19725.20384 or later (apply latest SharePoint security updates)
- Identify the current SharePoint Server build version by navigating to SharePoint Central Administration > System Settings > Manage farm servers
- Download and install the latest Microsoft Security Update for SharePoint Server from catalog.update.microsoft.com
- Ensure all servers in the SharePoint farm are updated to build 16.0.19725.20384 or later
- After applying the update, run the SharePoint Products Configuration Wizard on each server in the farm
- Verify the update was successful by checking the build number in Central Administration
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $11,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-47639 — 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-2026-47639 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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- 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
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