CVE-2025-53770: Microsoft SharePoint (Critical, CVSS 9.8)
- CVSS
- 9.8 Critical (v3.1)
- EPSS
- 100% chance of exploitation in the next 30 days (higher than 99.9% of CVEs)
- Exploited in the wild
- Yes, on CISA’s KEV list since Jul 20, 2025; used by ransomware
- Public exploit
- Yes, reported in a Metasploit module, Exploit-DB, a Nuclei template and 45 GitHub repositories
- Weakness
- CWE-502
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- Published
- Jul 20, 2025
- CISA fix-by date
- Jul 21, 2025 (for US federal agencies)
What it is
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.
Description from the National Vulnerability Database.
What to do
CISA: 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 disc
Check whether you run Microsoft SharePoint, then apply the vendor’s fix or mitigation from the advisories below. Because this flaw is exploited or has public exploit code, treat it as urgent and check for signs of compromise, not just the patch level.
Advisories and fixes
ThreatRoundup coverage
Storm-2603 Hid a SharePoint Webshell in Memory, Then Reached for Warlock
Sources: NVD, FIRST EPSS, CISA KEV, and public exploit databases (availability only). ThreatRoundup reports whether public exploit code exists but never links to it: fake proof-of-concepts that infect security researchers are common. This page updates automatically.