# CVE-2025-53770

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.

- Page: https://www.vulneraibility.com/cve/CVE-2025-53770
- CVSS: 9.8
- Known exploited: yes, in CISA KEV since 2025-07-20; CISA due date 2025-07-21; known ransomware use
- EPSS: 100.00%
- Public exploit code: 1 on Exploit-DB · 1 Metasploit module · 45 GitHub proofs of concept · 1 Nuclei template (first 2025-07-21)
- CISA SSVC: exploitation active, automatable yes, technical impact total (assessed 2025-07-20)
- Weakness: CWE-502
- Published: 2025-07-20

## Affected versions

- Microsoft Microsoft SharePoint Enterprise Server 2016: affected >= 16.0.0 and < 16.0.5513.1001
- Microsoft Microsoft SharePoint Server 2019: affected >= 16.0.0 and < 16.0.10417.20037
- Microsoft Microsoft SharePoint Server Subscription Edition: affected >= 16.0.0 and < 16.0.18526.20508

A version outside these ranges is not a statement that it is unaffected.

## References

- [patch] https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770
- [other] https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770
- [other] https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/
- [other] https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770
- [other] https://research.eye.security/sharepoint-under-siege/
- [other] https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/
- [other] https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack---no-patch-available/
- [other] https://x.com/Shadowserver/status/1946900837306868163
- [other] https://github.com/kaizensecurity/CVE-2025-53770
- [other] https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally
- [other] https://news.ycombinator.com/item?id=44629710
- [other] https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/
- [other] https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-flaw

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Summary, impact and action are written by the vulneraibility.com AI analysis pipeline from the CVE record, NVD, CISA and FIRST data; verify against the references.