CVE coverage
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CVE-2025-53770
CVSS 9.8
Actively exploited (KEV)
8 detections found
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.
Detection rules
| Source | Rule | Status | Updated |
|---|---|---|---|
| elastic | Unusual Web Config File Access | production | 2026-09-18 |
| splunk | Windows SharePoint Spinstall0 Webshell File Creation | production | 2026-05-13 |
| splunk | Windows SharePoint Spinstall0 GET Request | production | 2026-05-13 |
| splunk | Windows SharePoint ToolPane Endpoint Exploitation Attempt | production | 2026-05-13 |
| sigma | Suspicious File Write to SharePoint Layouts Directory | experimental | 2025-07-24 |
| sigma | Potential SharePoint ToolShell CVE-2025-53770 Exploitation - File Create | experimental | 2025-07-24 |
| sigma | Potential SharePoint ToolShell CVE-2025-53770 Exploitation Indicators | experimental | 2025-07-21 |
| sigma | SharePoint ToolShell CVE-2025-53770 Exploitation - Web IIS | experimental | 2025-07-21 |