CVE-2025-49706
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 authentication 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 vulnerability in Microsoft Office SharePoint involves improper authentication mechanisms that allow an unauthorized attacker to spoof legitimate users over a network. The issue stems from insufficient validation of authentication credentials, potentially enabling attackers to impersonate authorized users and gain unauthorized access to SharePoint resources.
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= 2016< 16.0.18526.20424= 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/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.
-
Identify SharePoint build versionOpen SharePoint Central Administration > System Settings > Manage server in this farm. Note the Configuration Database Version, or run Get-SPFarm | Select-Object BuildVersion in SharePoint Management ShellAffected if Build version equals 2016, is less than 16.0.18526.20424, or equals 2019
-
Confirm SharePoint product typeIn Central Administration > System Settings > Manage servers in this farm, verify whether the installation is SharePoint Server 2016, SharePoint Server 2019, or SharePoint Enterprise Server 2016Affected if Product is SharePoint Enterprise Server 2016, SharePoint Server 2016, or SharePoint Server 2019 with the version conditions above
-
Check authentication method configurationIn Central Administration > Application Management > Manage web applications > Authentication Providers, review the authentication type in use (Claims-based vs Classic mode, and any custom authentication providers)Affected if Any authentication provider is configured that could be subject to the spoofing bypass (this check identifies exposed attack surface)
You are affected if your SharePoint Server/Enterprise Server version matches 2016 exactly, is below 16.0.18526.20424, or is version 2019, AND uses the authentication method impacted by this vulnerability.
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 · scoped16.0.18526.20424
Apply the Microsoft security update for CVE-2025-49706 when available. Until then, implement network segmentation and monitor for suspicious authentication patterns.
SharePoint Server 2019: Update to version 16.0.18526.20424 or later; SharePoint Server 2016: Microsoft ended mainstream support in July 2024 - consider migrating to Microsoft 365 or extended security updates if available
- Obtain the security update for CVE-2025-49706 from the Microsoft Security Response Center (msrc.microsoft.com)
- Apply the update to all affected SharePoint servers in your environment
- After applying the update, verify the SharePoint version matches or exceeds 16.0.18526.20424
- Test critical SharePoint workflows and authentication processes to confirm proper functionality
- Document the update for compliance and audit purposes
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-2025-49706 — 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-2025-49706 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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