CVE-2025-53770

high-risk
Published 2025-07-20

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.

Do I need to act?

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88.7% chance of exploitation in next 30 days
EPSS score — higher than 11% of all CVEs
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CISA KEV: actively exploited in the wild
On the Known Exploited Vulnerabilities catalog — federal agencies must patch
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1 public exploit available
52405
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.8/10 Critical
NETWORK / LOW complexity

Affected Products (3)

Affected Vendors

Microsoft

References (13)

Vendor Advisory https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770
Exploit https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-sever...
Exploit https://github.com/kaizensecurity/CVE-2025-53770
Mitigation https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnera...
Issue Tracking https://news.ycombinator.com/item?id=44629710
Exploit https://research.eye.security/sharepoint-under-siege/
Press/Media Coverage https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-gl...
Press/Media Coverage https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-ex...
Mailing List https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-e...
Press/Media Coverage https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-expl...
Press/Media Coverage https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-m...
Third Party Advisory https://x.com/Shadowserver/status/1946900837306868163
US Government Resource https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-...
68
/ 100
high-risk
Severity 32/34 · Critical
Exploitability 27/34 · High
Exposure 9/34 · Low