Actively exploited · Published Jul 20, 2025 · Assigned by microsoft
CVE-2025-53770Microsoft SharePoint Server Remote Code Execution Vulnerability
Critical 9.8 Exploited Ransomware
In plain English
A critical-severity unsafe deserialization in Microsoft SharePoint Enterprise Server 2016 from Microsoft. Attackers are actively exploiting it in the wild (listed by CISA on July 20, 2025). It has been used in ransomware campaigns. The chance it is exploited in the next 30 days is estimated at 100.0% (higher than 99.9% of all known vulnerabilities). Ready-made attack tooling exists: Metasploit, Nuclei, public proof-of-concept code. 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.
CISA guidance
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.
Federal agencies must remediate by Jul 21, 2025.
Official description
Deserialization of untrusted data in on-premises Microsoft SharePoint Server allows an unauthorized attacker to execute code over a network. Microsoft is aware that an exploit for CVE-2025-53770 exists in the wild. Microsoft is preparing and fully testing a comprehensive update to address this vulnerability. In the meantime, please make sure that the mitigation provided in this CVE documentation is in place so that you are protected from exploitation.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft SharePoint Enterprise Server 2016 | 16.0.0 – before 16.0.5513.1001 |
| Microsoft | Microsoft SharePoint Server 2019 | 16.0.0 – before 16.0.10417.20037 |
| Microsoft | Microsoft SharePoint Server Subscription Edition | 16.0.0 – before 16.0.18526.20508 |
Weakness: CWE-502 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:W/RC:C
References
- Microsoft SharePoint Server Remote Code Execution Vulnerability vendor-advisory, patch
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770 government-resource
- https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/
- https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770
- https://research.eye.security/sharepoint-under-siege/
- https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/
- https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack---no-patch-available/
- https://x.com/Shadowserver/status/1946900837306868163
- https://github.com/kaizensecurity/CVE-2025-53770
- https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally
- https://news.ycombinator.com/item?id=44629710
- https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/
- https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-flaw