CVE-2025-53770
CRITICAL severity · CVSS 9.8 · Insecure deserialization · actively exploited (CISA KEV)
9.8CVSS CRITICAL ● exploited ⚠ ransomware
🔴 Actively exploited in the wild (CISA Known Exploited Vulnerabilities).
⚠ Known use in ransomware campaigns. Added to KEV 2025-07-20. US federal agencies must patch by 2025-07-21.
Summary
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.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactHigh
Availability impactHigh
Exploit probability (EPSS)88%
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products we track (1)
Recommendation
This vulnerability is being actively exploited in the wild — patch affected products urgently. Open any affected product above for its exact safe version.
Additional information
- NVD record
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770Advisory
- https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/Advisory
- https://research.eye.security/sharepoint-under-siege/Advisory
- https://news.ycombinator.com/item?id=44629710
- https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally
- https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/
- https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/Exploit
- https://github.com/kaizensecurity/CVE-2025-53770Exploit