CVE-2026-55019
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 authorized attacker to perform spoofing over a network.
In the news
Third-party coverage- Microsoft July 2026 Patch Tuesday fixes massive 570 flaws, 3 zero-days
- 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 a cross-site scripting (XSS) vulnerability in Microsoft Office SharePoint where improper input neutralization during web page generation allows an authenticated attacker to inject malicious scripts, enabling session hijacking and spoofing attacks against other users.
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< 16.0.19725.20434= 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
- 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 Central Administration, go to System Settings > Manage servers in this farm, and note the SharePoint version shown. Alternatively, run PowerShell command: (Get-SPFarm).BuildVersionAffected if Version is 2016, 2019, or below 16.0.19725.20434
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Confirm SharePoint build numberCheck the exact build version via PowerShell: Get-SPFarm | Select-Object -ExpandProperty BuildVersion. This returns a version string like 16.0.XXXX.XXXXXAffected if Build version number is less than 16.0.19725.20434
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Verify SharePoint web application is runningIn Central Administration, go to Application Management > Manage web applications. Confirm at least one web application is provisioned and running.Affected if Any web application is active - the XSS manifests in SharePoint web pages generated for users
You are affected if your SharePoint Server version is 2016 or 2019, or the build version is below 16.0.19725.20434 and web applications are accessible to authenticated users.
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 · scoped16.0.19725.20434
Apply Microsoft security patches for SharePoint when available; implement input validation and output encoding for user-supplied content; configure Content Security Policy headers to mitigate XSS execution.
SharePoint Server build 16.0.19725.20434 or later (for on-premises SharePoint 2016/2019)
- 1. Identify current SharePoint Server build version via SharePoint Admin Center or PowerShell: (Get-SPFarm).BuildVersion
- 2. Confirm affected version is < 16.0.19725.20434, or determine if running SharePoint Server 2016 or 2019
- 3. Review Microsoft Security Response Center (msrc.microsoft.com) for the corresponding security update bulletin
- 4. Download and apply the relevant security update from Microsoft Update Catalog or through Windows Server Update Services (WSUS)
- 5. After applying the update, verify the build version has been incremented to 16.0.19725.20434 or higher
- 6. Test critical SharePoint workflows and web parts to confirm normal operation post-update
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 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 $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-55019 — 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-2026-55019 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