Microsoft
CVE-2025-53770
CRITICAL
Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Lifecycle Timeline
5DescriptionCVE.org
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.
AnalysisAI
Microsoft SharePoint Server contains a deserialization vulnerability allowing unauthenticated remote code execution over the network, with active exploitation confirmed and patches pending full release.
Technical ContextAI
The CWE-502 deserialization flaw allows unauthenticated attackers to send crafted serialized data to SharePoint Server, which deserializes it without proper validation, leading to arbitrary code execution in the SharePoint application context.
Affected ProductsAI
Microsoft SharePoint Server (on-premises, affected versions)
RemediationAI
Apply Microsoft's mitigation steps immediately. Install the comprehensive update when available. Restrict network access to SharePoint. Monitor for suspicious deserialization patterns in IIS logs.
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External POC / Exploit Code
Leaving vuln.today