CVE-2025-53770
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
This vulnerability is in the CISA Known Exploited Vulnerabilities catalog: attackers are using it. If you run SharePoint, fix it now.
CISA 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.
US federal civilian agencies must remediate by Jul 21, 2025.
Patch status
No official fix confirmed yet
Until a fix ships, follow the vendor's mitigations and CISA's required action, limit exposure of affected systems, and watch this record for a patch.
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.
Source: NIST National Vulnerability Database. Official vulnerability data, reproduced as published.
Affected products
| Product | Vendor | Affected versions | Fixed in | Source |
|---|---|---|---|---|
| SharePoint | Microsoft | — | — | KEV |
| SharePoint Server | Microsoft | < 16.0.18526.20508; 2016; 2019 | 16.0.18526.20508 | NVD |
Sources: KEV = CISA Known Exploited Vulnerabilities catalog; NVD = NIST National Vulnerability Database.
Intelligence timeline
Developments from the last 30 days, newest first.
- CVSS scoredUpdateKEV
CVE-2025-53770 scored CVSS 9.8: Microsoft SharePoint, Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
CISA lists this as exploited in the wild and known to be used in ransomware campaigns. Unpatched SharePoint systems are exposed to active attacks now.
Basis: NIST National Vulnerability Database
1 earlier event is available with a subscription. See plans.
Coverage
We have not published a story about this vulnerability yet.