CVE-2025-53770
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
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.
CRITICAL · CVSS 9.8
⚠ CISA KEV
EPSS 0.88536
Ransomware: known
Act now
- Listed on CISA KEV (known exploited in the wild)
- Linked to known ransomware campaigns
- SSVC exploitation status: active
- EPSS ≥ 0.50 - high probability of exploitation in the next 30 days
- EPSS percentile: top 0% of all CVEs by exploitation likelihood
- Public exploit or PoC is available
- SSVC automatable: yes - attacks can be scripted at scale
- CVSS base score ≥ 7.0