Vulnerabilities/Microsoft/CVE-2025-53770
CVE-2025-53770: Microsoft SharePoint Deserialization of Untrusted Data Vulnerability
CISA KEV entry · Last checked 30 Oct 2026, 12:10 UTC
Exploitation confirmedRansomware use knownFix: Unknown
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.
Recommended action
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.
CISA due date 21 Jul 2025 · CWE-502
Am I affected?
| Product | Affected versions | Fixed in |
|---|---|---|
| Microsoft SharePoint Enterprise Server 2016 | 16.0.0 to before 16.0.5513.1001 | Unknown |
| Microsoft SharePoint Server 2019 | 16.0.0 to before 16.0.10417.20037 | Unknown |
| Microsoft SharePoint Server Subscription Edition | 16.0.0 to before 16.0.18526.20508 | Unknown |
No source states a fixed version. Check the vendor advisory below.
Before you patch
Restart
See vendor guidance.Known issues
Check release notes.Verification
Confirm installed version.Timeline
- 20 Jul 2025 · Added to CISA KEV
- 21 Jul 2025 · CISA due date
Sources checked
| CISA KEV | 30 Oct 2026, 12:10 UTC |
| CVE List v5 | 30 Oct 2026, 12:11 UTC |
| NVD | 30 Oct 2026, 12:10 UTC |
| FIRST EPSS | 30 Oct 2026, 12:11 UTC |
Data from CISA, MITRE, NVD and FIRST. Sources and licences.