CVE-2025-53770
Deserialization of untrusted data in on-premises Microsoft SharePoint Server allows an unauthorized attacker to execute code over a network…
Browse: All 2025 CVEs · All vendors
- CVSS score
- 9.8 Critical
- CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H- CISA KEV
- Yes — actively exploited (added 2025-07-20, remediation due 2025-07-21)
- Ransomware
- Known ransomware campaign use
- Weakness (CWE)
- CWE-502
- Published
- 2025-07-20
- Last modified
- 2026-08-04
- NVD status
- Analyzed
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.
Affected products
- microsoft sharepoint server
Affected ranges per NVD CPE data; confirm exact versions in the vendor advisory.
Required action (CISA)
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. Federal remediation deadline: 2025-07-21.
How to prioritize this
This vulnerability is on the CISA KEV list, meaning it is being actively exploited — treat it as urgent regardless of the raw CVSS number. Use the live CVE lookup for the latest NVD data, and the CVSS 3.1 calculator to model your own environmental score.
References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770
- https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/
- https://github.com/kaizensecurity/CVE-2025-53770
- https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/
- https://news.ycombinator.com/item?id=44629710
- https://research.eye.security/sharepoint-under-siege/
- https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally
- https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/
FAQ
Is CVE-2025-53770 actively exploited?
Yes. CISA added CVE-2025-53770 to its Known Exploited Vulnerabilities (KEV) catalog on 2025-07-20, with a federal remediation deadline of 2025-07-21. A KEV listing means real-world exploitation is confirmed, so patching this should be prioritized above many higher-CVSS bugs that aren't being exploited.
What is the CVSS score of CVE-2025-53770?
CVE-2025-53770 has a CVSS base score of 9.8 (Critical). Its vector string is CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Related vulnerabilities
- CVE-2026-55040 — Microsoft SharePoint
- CVE-2026-50522 — Microsoft SharePoint
- CVE-2026-58644 — Microsoft SharePoint
- CVE-2026-20963 — Microsoft SharePoint
- CVE-2025-49704 — Microsoft SharePoint
- CVE-2025-49706 — Microsoft SharePoint
Data source: NVD & CISA KEV. Shown as-is; nothing added. Last generated from NVD data — re-check the live tool for updates.
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