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.

Weakness: CWE-502.

Attack vector

Network

Attack complexity

Low

Privileges required

None

User interaction

None

Scope

Unchanged

Confidentiality impact

High

Integrity impact

High

Availability impact

High

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…

Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition. NVD's record lists the exact affected versions.

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