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Vulnerabilities

Vulnerability · CVE-2026-56164

Microsoft SharePoint Server Missing Authentication for Critical Function Vulnerability

Published Jul 14, 2026 · catalog updated Jul 14, 2026 · Microsoft SharePoint

Severity
Critical9.8
Known exploitation
CISA KEV and VulnCheck KEV
EPSS
1.0%
Remediation
Remediation guidance
Affected products
cpe microsoft/sharepoint server · vendor Microsoft SharePoint · vendor Microsoft SharePoint Server

Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.

Technical analysis

Mechanism and impact are interpreted from ingested advisories — not independent exploit research.

  • CWE classification

    Missing Authentication for Critical Function

  • Prerequisites and impact

    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.

How to fix CVE-2026-56164

  • Recommended remediation

    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. CISA due date Jul 17, 2026.

  • Official advisories

What to do

Three reads of the same public record: the decision, the versions on file, and the signals. Confirm the vendor advisory before you patch. This page does not publish exploit steps.

Executive

Treat this as an active risk. CVE-2026-56164 is a critical issue in Microsoft SharePoint (CVSS 9.8). CISA lists it as known exploited since Jul 14, 2026. Next step: 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.

System administrator

Check whether Microsoft SharePoint is installed. Ranges on record: microsoft/sharepoint server; microsoft/sharepoint server (2016); microsoft/sharepoint server (2019); Microsoft SharePoint. 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.

Security analyst

CVSS 9.8. EPSS 1.0%. CISA lists it as known exploited since Jul 14, 2026. Weaknesses: CWE-306. Sources: cisa_kev, cve_org, epss, jpcert. Exploit links, when listed below, point at the original publisher.

Related intelligence

  • Exploitation evidence

    Confirmed in CISA KEV since Jul 14, 2026. Listed in CISA KEV and VulnCheck KEV.

  • Safe detection guidance

    Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Jul 14, 2026 · Catalog

    Detected

    Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.

  2. Jul 14, 2026 · CISA KEV

    Known exploited

    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

  3. Jul 14, 2026 · Catalog

    Updated

    Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.

  4. Jul 17, 2026 · CISA KEV

    Remediation due

    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

Affected versions

Enter an installed version to get a verified affected / not-affected result against the ranges below.

  • cpe microsoft/sharepoint serverversion unspecified
  • cpe microsoft/sharepoint server2016
  • cpe microsoft/sharepoint server2019
  • vendor Microsoft SharePointversion unspecified
  • vendor Microsoft SharePoint Serverversion unspecified

Sources

  • CISA KEVConfirmed exploitationCVE-2026-56164

    Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.

    cisa.gov
  • CVE.orgVulnerability recordCVE-2026-56164

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2026-56164

    30-day exploitation probability 1.0%

    first.org
  • JPCERT/CCGovernment advisoryCVE-2026-56164

    [Updated] Microsoft Releases July 2026 Security Updates

    jpcert.or.jp
  • NIST NVDVulnerability recordCVE-2026-56164

    Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.

    nvd.nist.gov
  • VulnCheck KEVConfirmed exploitationCVE-2026-56164

    Microsoft SharePoint contains a missing authentication for critical function vulnerability that allows an unauthorized attacker to elevate privileges over a network.

    vulncheck.com

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.