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.
Metrics
CVSS 3.1 9.8/10
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HWeakness enumeration
Affected software
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft SharePoint Enterprise Server 2016 | >= 16.0.0, < 16.0.5513.1001 |
| Microsoft | Microsoft SharePoint Server 2019 | >= 16.0.0, < 16.0.10417.20037 |
| Microsoft | Microsoft SharePoint Server Subscription Edition | >= 16.0.0, < 16.0.18526.20508 |
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770Vendor Advisory
- https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/Exploit, Press/Media Coverage
- https://github.com/kaizensecurity/CVE-2025-53770Exploit
- https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/Mitigation, Vendor Advisory
- https://news.ycombinator.com/item?id=44629710Issue Tracking
- https://research.eye.security/sharepoint-under-siege/Exploit, Mitigation, Third Party Advisory
- https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globallyPress/Media Coverage
- https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/Press/Media Coverage
- https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770Mailing List, Third Party Advisory, US Government Resource
- https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-flawPress/Media Coverage
- https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack---no-patch-available/Press/Media Coverage
- https://x.com/Shadowserver/status/1946900837306868163Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770US Government Resource
Timeline
- Published
- Jul 20, 2025
- Last modified
- Aug 4, 2026
- Added to CISA KEV
- Jul 20, 2025
- NVD status
- Analyzed