CVE-2025-30378
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 · uneditedDeserialization of untrusted data in Microsoft Office SharePoint 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 confidenceThis is a deserialization vulnerability in Microsoft Office SharePoint where untrusted data is deserialized without proper validation, potentially allowing an unauthorized attacker to execute arbitrary code on the affected SharePoint server.
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< 16.0.18526.20286= 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
- High
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/PR:N/UI:R/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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Check SharePoint Server build versionOpen SharePoint Management Shell and run: (Get-SPFarm).BuildVersionAffected if The version number is less than 16.0.18526.20286 or matches 16.0.x versions for SharePoint 2016/2019 editions
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Identify SharePoint edition and exact versionIn Central Administration, go to System Settings > Manage servers in this farm. Note the SharePoint version and build number.Affected if Version shows SharePoint Server 2016 or 2019 (any build), or version is below 16.0.18526.20286 for newer editions
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Check for deserialization-enabled featuresReview installed Farm Solutions and Web Parts in Central Administration under System Settings > Manage farm solutions. Look for custom or third-party solutions that handle serialized data.Affected if Any custom farm solutions or non-Microsoft web parts that accept or process serialized objects are deployed
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Verify network exposure of SharePoint servicesCheck firewall rules and IIS bindings to confirm which network interfaces SharePoint web applications are bound to.Affected if SharePoint is accessible from untrusted networks without proper authentication proxies
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Audit SharePoint incoming data handlersReview IIS logs and SharePoint ULS logs for patterns related to ViewState, SOAP, or other serialized data endpoints.Affected if Logs show frequent deserialization endpoints being accessed from external sources
You are affected if your SharePoint Server build is below 16.0.18526.20286, or is exactly version 2016 or 2019, and the server handles untrusted serialized data inputs.
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 · scoped16.0.18526.20286
Apply the latest Microsoft security update for SharePoint to remediate this vulnerability.
SharePoint Server version 16.0.18526.20286 or later
- 1. Review the Microsoft Security Response Center (msrc.microsoft.com) advisory for CVE-2025-30378 for complete details
- 2. Identify your current SharePoint Server version via SharePoint Administration Center or Central Administration
- 3. For SharePoint Server 2016 and 2019, apply the Microsoft security update corresponding to CVE-2025-30378
- 4. Alternatively, upgrade SharePoint Server to version 16.0.18526.20286 or later which contains the fix
- 5. After applying the patch or upgrade, verify the SharePoint Server version reflects the fixed build
- 6. Test critical SharePoint workflows to ensure functionality is maintained
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,088.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-30378 — 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-2025-30378 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