Microsoft SharePoint Improper Authentication
CVE-2025-49706 is a medium-severity improper authentication vulnerability in Microsoft SharePoint Enterprise Server 2016 from Microsoft, with a CVSS 3.1 base score of 6.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 16.0.5508.1000 as the first without the flaw, so updating Microsoft SharePoint Enterprise Server 2016 to that release or later removes the exposure. CISA added it to the Known Exploited Vulnerabilities catalogue on July 22, 2025, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Update Microsoft SharePoint Enterprise Server 2016 to 16.0.5508.1000 or a later version.
- Update Microsoft SharePoint Server 2019 to 16.0.10417.20027 or a later version.
- Update Microsoft SharePoint Server Subscription Edition to 16.0.18526.20424 or a later version.
- CISA's required action: 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.
- Read the advisory on msrc.microsoft.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Microsoft | Microsoft SharePoint Enterprise Server 2016 | 16.0.0 up to, but not including, 16.0.5508.1000 | 16.0.5508.1000 |
| Microsoft | Microsoft SharePoint Server 2019 | 16.0.0 up to, but not including, 16.0.10417.20027 | 16.0.10417.20027 |
| Microsoft | Microsoft SharePoint Server Subscription Edition | 16.0.0 up to, but not including, 16.0.18526.20424 | 16.0.18526.20424 |
| Microsoft | Sharepoint Enterprise Server | 2016 | Not stated |
| Microsoft | Sharepoint Server | before 16.0.18526.20424; 2019 | 16.0.18526.20424 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- LowSome restricted data can be read.
- Integrity
- LowLimited modification of data is possible.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N. Scored by CNA (microsoft.com).
Official description
Improper authentication in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a network.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Authentication
When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.
How developers prevent this class of flaw
- Use an authentication framework or library such as the OWASP ESAPI Authentication feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: active, automatable: no, technical impact: partial).
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-49706US Government Resource
Other vulnerabilities in Microsoft SharePoint Enterprise Server 2016
- 9.3 Critical severity
- 8.8 High severity
Microsoft SharePoint Code Injection Exploited
Recent Improper Authentication vulnerabilities
- 7.3 High severity
- 7.6 High severity
- 8.8 High severity
- 8.8 High severity
- 9.6 Critical severity
- 8.8 High severity
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