CVE-2025-53770

CRITICAL CISA KEV EPSS 100.0%
Published Jul 20, 202511mo ago · Modified Jun 17, 20261w ago
9.8 CVSS 3.1
Critical
Find Similar
Published Jul 20, 2025 11mo ago
Last Modified Jun 17, 2026 1w ago
KEV Listed Jul 20, 2025 11mo ago
KEV Due Jul 21, 2025 344d overdue

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.

CVSS Details

Base Score
9.8
Exploitability
3.9
Impact
5.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

CISA Known Exploited Overdue 344d
Added
Jul 20, 2025
Due
Jul 21, 2025

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.

EPSS Exploit Probability
100.0% percentile
Exploit & Patch Status
Actively Exploited (KEV)
No Patch Available

Weaknesses 1

CWE-502 Deserialization of Untrusted Data Validation

Affected Products 3

VendorProductVersionRange
microsoftsharepoint_server* <16.0.18526.20508
microsoftsharepoint_server2016any
microsoftsharepoint_server2019any

References 13

  • arstechnica.com https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/
    ExploitPress/Media Coverage
  • github.com https://github.com/kaizensecurity/CVE-2025-53770
    Exploit
  • msrc.microsoft.com https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/
    MitigationVendor Advisory
  • msrc.microsoft.com https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770
    Vendor Advisory
  • news.ycombinator.com https://news.ycombinator.com/item?id=44629710
    Issue Tracking
  • research.eye.security https://research.eye.security/sharepoint-under-siege/
    ExploitMitigationThird Party Advisory
  • therecord.media https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally
    Press/Media Coverage
  • bleepingcomputer.com https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/
    Press/Media Coverage
  • cisa.gov https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770
    US Government Resource
  • cisa.gov https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770
    Mailing ListThird Party AdvisoryUS Government Resource
  • darkreading.com https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-flaw
    Press/Media Coverage
  • forbes.com https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack---no-patch-available/
    Press/Media Coverage
  • x.com https://x.com/Shadowserver/status/1946900837306868163
    Third Party Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.