CVE-2025-49706 Microsoft SharePoint Improper Authentication Vulnerability
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.
From the CISA KEV catalogue version 2026.11.06, with Cybergen analysis. Updated 6 Nov 2026.
Should You Worry?
- CISA confirmed exploitation in the wild and added it to the Known Exploited Vulnerabilities catalogue on 22 Jul 2025.
- CISA lists it as known to be used in ransomware campaigns.
- Rated Medium severity (CVSS 6.5, scored by Vendor).
- This product type is often exposed to the internet, which is where attackers scan for it first.
- It has been in the catalogue for 472 days. Systems still unpatched now have almost certainly been scanned for it.
What It Is
Improper authentication in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network.
Affected Versions
| Product | Versions |
|---|---|
| Microsoft Microsoft SharePoint Enterprise Server 2016 | 16.0.0 to before 16.0.5508.1000 |
| Microsoft Microsoft SharePoint Server 2019 | 16.0.0 to before 16.0.10417.20027 |
| Microsoft Microsoft SharePoint Server Subscription Edition | 16.0.0 to before 16.0.18526.20424 |
From the public CVE record, as supplied by the vendor. Always confirm against the vendor advisory.
What To Do Now
- 1
Find it
Search your asset inventory and external attack surface for Microsoft SharePoint. Include cloud images, appliances and anything a supplier runs for you.
Attack Surface Management - 2
Fix it
Disconnect public-facing versions of SharePoint Server that have reached their end-of-life (EOL) or end-of-service (EOS) to include SharePoint Server 2013 and earlier versions. For supported versions, please follow the mitigations according to CISA (URL listed below in Notes) and vendor instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.
Vulnerability Management - 3
Hunt for compromise
If an affected system was reachable before you patched, assume it may have been hit. Check logs, new accounts, web shells and outbound connections from the date of exposure.
Incident Response - 4
Prove it is fixed
Rescan or test the system after patching. Upgrades that fail silently and forgotten secondary instances are common.
Penetration Testing
The Compliance Clock
General guidance, not legal advice. Your obligations depend on your sector, scope and jurisdiction.
Not Sure If You Are Exposed?
Our attack surface and vulnerability teams can check your internet-facing estate for CVE-2025-49706 and every other exploited flaw on the list.