CVE-2026-45453
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 unauthorized attackers to perform spoofing attacks over a network by injecting client-side scripts that execute in the context of the victim's browser.
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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Retrieve SharePoint Server build versionOpen SharePoint Central Administration > System Settings > Manage servers in this farm, or run PowerShell: (Get-SPFarm).BuildVersionAffected if The build version shown is lower than 16.0.19725.20384, or the version corresponds to SharePoint Server 2016 or 2019
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Confirm SharePoint edition and major versionIn Central Administration > Upgrade and Migration > Check product and patch installation status, or run PowerShell: Get-SPFarm | Select-Object BuildVersion, VersionAffected if The displayed version indicates SharePoint Server 2016 or SharePoint Server 2019 (any build)
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Verify the SharePoint build against the fixed versionCompare your recorded build number (for example, 16.0.14727.XXXX or 16.0.17424.XXXX) against the fixed build 16.0.19725.20384Affected if Your build number is less than 16.0.19725.20384, indicating an unpatched version
You are affected if your SharePoint Server is version 2016 or 2019, or if your build number is below 16.0.19725.20384, as these versions lack the XSS input validation fix.
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 security patches for SharePoint when available; implement input validation and output encoding on SharePoint pages; consider enabling SharePoint's Anti-XSS protections.
- Consultation4.0 h
- Implementation4.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-45453 — 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-2026-45453 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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