CVE-2025-53770
Microsoft SharePoint
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.
Exploitation status
- CISA has confirmed this is being exploited in the wild. That is an observation of real attacks, not a prediction.
- It is known to have been used in ransomware campaigns.
- US federal civilian agencies are required to remediate it by 2025-07-21. That deadline does not bind private companies, but it is a reasonable benchmark for how urgently CISA views it.
Required 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’s wording, unedited.
Scoring
- CVSS
- Not yet scored
Dates
- Published
- 2025-07-20
- Added to KEV
- 2025-07-20
- Remediation due
- 2025-07-21
- Sources
- CISA KEV