CVE-2025-53770
Analyzed
Published: 20 Jul 2025, 01:06
Last modified:26 Feb 2026, 17:50
Vulnerability Summary
Overall Risk (default)
high
70/100 CVSS Score
9.8 CRITICAL
v3.1 (cve.org)
EPSS Score
91.05% CRITICAL
91% probability +0.10%
KEV
Listed
CIRCL • CISA
2 listings
Ransomware
Known Use
Public exploits
5 found
Dark Web
Not detected
Timeline
20 Jul 2025, 01:06
Published
Vulnerability first disclosed
20 Jul 2025, 00:00
Added to CIRCL KEV
Added to Known Exploited Vulnerabilities catalog
20 Jul 2025, 00:00
Added to CISA KEV
Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
21 Jul 2025, 00:00
CISA Remediation Due
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.
26 Feb 2026, 17:50
Last Modified
Vulnerability information updated
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 Metrics
- v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:W/RC:C
- v3.1•CRITICAL•Score: 9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Trends
Current EPSS score: 91.05%• Percentile: 100%
Techniques & Countermeasures
- CWE-502•Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
Affected Systems
- microsoft•microsoft sharepoint enterprise server 2016
≥ 16.0.0, < 16.0.5513.1001
- microsoft•microsoft sharepoint server 2019
≥ 16.0.0, < 16.0.10417.20037
- microsoft•microsoft sharepoint server subscription edition
≥ 16.0.0, < 16.0.18526.20508
- Unknown•SharePoint Server
< 16.0.18526.20508 | 2016 | 2019
References (13)
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770
- https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/
- https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770
- https://research.eye.security/sharepoint-under-siege/
- https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/
- https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack---no-patch-available/
- https://x.com/Shadowserver/status/1946900837306868163
- https://github.com/kaizensecurity/CVE-2025-53770
- https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally
- https://news.ycombinator.com/item?id=44629710
- https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/
- https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-flaw