CASCACascade Atlas

Evidence dossier

CVE-2025-53770

Microsoft SharePoint Server Remote Code Execution Vulnerability

84.5–99.5Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

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.

State
PUBLISHED
Published
Jul 20, 2025
Updated
Feb 26, 2026
Evidence coverage
85%
CISA KEVCatalog member

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.

FIRST EPSS99.98%

2026-07-18 · v2026.06.15 · percentile 100.0%

Source stateNo scored conflict

Distinct CVSS assessments remain side by side; none are averaged.

Source comparison

Who said what

CISA-ADPindependent enrichment
container

CISA ADP Vulnrichment

CVEderivative copy
container

CVE Program Container

microsoftoriginal assertion
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Microsoft SharePoint Server Remote Code Execution Vulnerability

CISA KEVoriginal assertion
observed_exploitation

Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.999790000000; percentile 0.999800000000

Applicability

Cited product scope

Trace impact →
MicrosoftMicrosoft SharePoint Enterprise Server 2016
[{"status": "affected", "version": "16.0.0", "lessThan": "16.0.5513.1001", "versionType": "custom"}]unknown
MicrosoftMicrosoft SharePoint Server 2019
[{"status": "affected", "version": "16.0.0", "lessThan": "16.0.10417.20037", "versionType": "custom"}]unknown
MicrosoftMicrosoft SharePoint Server Subscription Edition
[{"status": "affected", "version": "16.0.0", "lessThan": "16.0.18526.20508", "versionType": "custom"}]unknown
Unknown vendorUnknown product
cpe:2.3:a:microsoft:sharepoint_server:2016:*:*:*:enterprise:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:microsoft:sharepoint_server:2019:*:*:*:*:*:*:*supported
Unknown vendorUnknown product
cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:*; end excluding 16.0.18526.20508supported

Assessments

CVSS by origin

9.8
secure@microsoft.comCVSS 3.1 · role SecondaryCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.8
microsoftCVSS 3.1 · role unknownCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:F/RL:W/RC:C

Limitations and unknowns

  • KEV membership is authoritative for the catalog, not proof of exposure in any environment.
  • EPSS is a dated model probability and not an individual-environment prediction.
  • Affected or fixed status applies only to the exact cited product and version scope; unresolved scope remains unknown.
  • NVD-carried upstream facts remain derivative and are not independent corroboration.
  • Only NVD metrics validated under the generation-bound calculator are Public Priority eligible; direct CVE record metrics remain display-only.
  • NVD CVSS source eligibility is closed: NVD-authored, exact record-source, or registered same-CVE container origin; unmapped sources remain display-only.
  • Factor D is unknown in Public Core because no accepted canonical mapping-obligation ledger is present.
  • Core replay supports the active and immediately prior generation; retrospective valid-at replay is deferred.