Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
Summary
Microsoft SharePoint Server on-premises contains a deserialization of untrusted data vulnerability that could allow an unauthorized attacker to execute code over a network. This vulnerability could be chained with CVE-2025-53771. CVE-2025-53770 is a patch bypass for CVE-2025-49704, and the updates for CVE-2025-53770 include more robust protection than those for CVE-2025-49704.
In-depth triage · Auto channel
No in-depth report has been generated yet (DR-003 v2 AI pipeline is under construction).
Affected products
- Microsoft:SharePoint
- :
Sources
- CISA KEV DATABASE
- NVD DATABASE
CH-4 Twitter/X Fair-Use Reference
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Original author
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Original Links
- https://nvd.nist.gov/vuln/detail/CVE-2025-53770 advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog kev
- https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770; reference
- https://www.microsoft.com/en-us/security/blog/2025/07/22/disrupting-active-exploitation-of-on-premises-sharepoint-vulnerabilities/ reference
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770 reference
- https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/ Exploit
- https://github.com/kaizensecurity/CVE-2025-53770 Exploit
- https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/ Mitigation
- https://news.ycombinator.com/item?id=44629710 Issue Tracking
- https://research.eye.security/sharepoint-under-siege/ Exploit
- https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally Press/Media Coverage
- https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/ Press/Media Coverage
- https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770 Mailing List
- https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-flaw Press/Media Coverage
- https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack---no-patch-available/ Press/Media Coverage
- https://x.com/Shadowserver/status/1946900837306868163 Third Party Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770 US Government Resource
Timeline
- kev_added CISA KEV
- kev_ingest CISA KEV
- nvd_ingest NVD