MEDIUMCVSS6.5

Actively Exploited

KB5002741: Windows Server Security Update (July 2025)

Microsoft SharePoint contains an improper authentication vulnerability that allows an authorized attacker to perform spoofing over a network. Successfully exploitation could allow an attacker to view sensitive information and make some changes to disclosed information. This vulnerability could be chained with CVE-2025-49704. CVE-2025-53771 is a patch bypass for CVE-2025-49706, and the updates for CVE-2025-53771 include more robust protection than those for CVE-2025-49706.

Published Jul 8, 2025 · Updated May 29, 2026

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Why patchRisk explained in plain English

Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve partial data exposure, partial data tampering. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2025-07-23 under CISA BOD 22-01.

How the attack worksNo clicks needed

This is a Improper Authentication (CWE-287) vulnerability in Microsoft SharePoint. Improper authentication in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

📧

Phishing link

→

🖼

Malicious file

🔓

Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

●SharePoint Administrators

●IT Security

●Running sharepoint enterprise server: 2016; sharepoint server: v < 16.0.18526.20424, 2019

Fixed inKB5002741, KB5002744, KB5002751 (applies to 3 product versions) — build 16.0.10417.20027, 16.0.18526.20424+

Real-world incidentsWhat we've seen

Used in known ransomware campaigns. Threat-research write-up: https://www.microsoft.com/en-us/security/blog/2025/07/22/disrupting-active-exploitation-of-on-premises-sharepoint-vulnerabilities/

How to patch

Manual download

For air-gapped servers or out-of-band deployment. Microsoft Update Catalog returns every OS-version variant of this update.

↗ Microsoft Update CatalogKB5002741

Manual remediation steps

Apply the Microsoft Security Update

Microsoft has released an official security update that fixes this vulnerability.

Required KB Updates

KB5002741 — https://support.microsoft.com/help/5002741

KB5002744 — https://support.microsoft.com/help/5002744

KB5002751 — https://support.microsoft.com/help/5002751

Supersedes: KB5002729, KB5002732, KB5002736

Affected Products

Microsoft SharePoint Enterprise Server 2016

Microsoft SharePoint Server 2019

Microsoft SharePoint Server Subscription Edition

Fixed Build Numbers

16.0.10417.20027

16.0.18526.20424

16.0.5508.1000

Installation Methods

Windows Update (recommended)

Settings → Windows Update → Check for updates

The security update is offered if your system is in scope

Restart when prompted (may or may not be required for this update)

Microsoft Update Catalog (manual download)

Open https://catalog.update.microsoft.com

Search for KB5002741

Download the package matching your OS architecture and Windows build

Run the .msu installer with administrator privileges

Restart when prompted

WSUS / SCCM / Intune

Approve KB5002741 for the affected products in your update management console.

Microsoft Download Center Links

https://www.microsoft.com/en-us/download/details.aspx?id=108257

https://www.microsoft.com/en-us/download/details.aspx?id=108259

https://www.microsoft.com/en-us/download/details.aspx?id=108262

Verification

Confirm the update is installed:

Get-HotFix | Where-Object { $_.HotFixID -in @('KB5002741','KB5002744','KB5002751') }

References

Microsoft Security Response Center: https://www.microsoft.com/en-us/security/blog/2025/07/22/disrupting-active-exploitation-of-on-premises-sharepoint-vulnerabilities/

KB article: https://support.microsoft.com/help/5002741

KB article: https://support.microsoft.com/help/5002744

KB article: https://support.microsoft.com/help/5002751

NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2025-49706

CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-49706