CASCACascade Atlas

Evidence dossier

CVE-2026-58644

Microsoft SharePoint Remote Code Execution Vulnerability

66.9–81.9Priority evidence range
As known Jul 19, 2026, 5:00 AM UTCgen-56ccdaf9

Normalized restatement

Deserialization of untrusted data in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

State
PUBLISHED
Published
Jul 14, 2026
Updated
Jul 17, 2026
Evidence coverage
85%
CISA KEVCatalog member

Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.

FIRST EPSS1.47%

2026-07-18 · v2026.06.15 · percentile 70.7%

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

microsoftoriginal assertion
container

Microsoft SharePoint Remote Code Execution Vulnerability

CISA KEVoriginal assertion
observed_exploitation

Microsoft SharePoint Deserialization of Untrusted Data Vulnerability

FIRST EPSSoriginal assertion
model_probability

Probability 0.014650000000; percentile 0.707360000000

Applicability

Cited product scope

Trace impact →
MicrosoftMicrosoft SharePoint Enterprise Server 2016
[{"status": "affected", "version": "16.0.0", "lessThan": "16.0.5556.1005", "versionType": "custom"}]unknown
MicrosoftMicrosoft SharePoint Server 2019
[{"status": "affected", "version": "16.0.0", "lessThan": "16.0.10417.20153", "versionType": "custom"}]unknown
MicrosoftMicrosoft SharePoint Server Subscription Edition
[{"status": "affected", "version": "16.0.0", "lessThan": "16.0.19725.20384", "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 16.0.19725.20434supported

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:O/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.