CVE · Exploited · On CISA KEV

CVE-2025-53770

Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

9.8: CVSS 3.1
1: story
JUL 20: added to KEV

Severity: 9.8 Critical · vendor score
Vendor: Microsoft
Product: SharePoint
Published: Jul 20, 2025
Added to KEV: Jul 20, 2025
KEV deadline: Jul 21, 2025
Ransomware use: Known
Weakness: CWE-502

What it is

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.

From CISA's Known Exploited Vulnerabilities catalog

Decipher coverage · 1 story

Newest first ↑

JUL 24
IntrusionsChinese Attackers Target SharePoint CVE-2025-53770Three separate Chinese threat groups are exploiting a set of recently disclosed vulnerabilities in on-premises Microsoft SharePoint installations, and Microsoft and CISA are urging companies that haven’t yet updated their installations to do so as quickly as possible. Microsoft first published information about the two flaws (CVE-2025-53770 and CVE-2025-53771) on July 19 after seeing active…DENNIS FISHER · 1 MIN

Official references

6 sources

Registries

RegistryNVDScore, weakness and every reference RegistryCVE.orgThe official CVE record RegistryCISA KEVKnown exploited, with the federal deadline

Advisories, fixes & analysis

Vendor advisorymsrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770 Fixmsrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770 Exploitresearch.eye.security/sharepoint-under-siege