CVE-2026-56164
criticalpriority · act · 90OT risk · criticalKEV · exploitedEPSS 0.010 · 63 %ileexploit · PoCDEEUNLRUUSadded 2026-07-14remediate by 2026-07-17
required action 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.
EPSS · scored 2026-10-24
Microsoft SharePoint Server Missing Authentication for Critical Function Vulnerability
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedMicrosoft SharePoint Enterprise Server 2016msrc_csaf
16.0.5561.1001:Security Update:https://support.microsoft.com/help/5002891
https://support.microsoft.com/help/5002891 - FixedMicrosoft SharePoint Server 2019msrc_csaf
16.0.10417.20175:Security Update:https://support.microsoft.com/help/5002883
https://support.microsoft.com/help/5002883 - FixedMicrosoft SharePoint Server Subscription Editionmsrc_csaf
16.0.19725.20434:Security Update:https://support.microsoft.com/help/5002882
https://support.microsoft.com/help/5002882
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 5.3–9.8
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (2)
Public proof-of-concept and weaponised exploit code.
- sentinel-aidefense/CVE-2026-56164-EXPCVE-2026-56164 EOP ExploitPoC · poc_in_github
affected products (55)
Products and version ranges known to be affected.
- Microsoft SharePoint Enterprise Server 2016all versionscert_bundDEcpe:/a:microsoft:sharepoint:enterprise_server_2016
- Microsoft SharePoint Server Subscription Editionall versionscert_bundDEcpe:/a:microsoft:sharepoint:server_subscription_edition
advisories (3)
Vendor and ecosystem advisories describing this.
- NCSC-2026-0237Kwetsbaarheden verholpen in Microsoft OfficeNL2026-07-14csaf · ncsc_nlNL
Microsoft heeft kwetsbaarheden verholpen in diverse Office producten, zoals Word, Excel, Powerpoint en SharePoint.
- WID-SEC-W-2026-2317Microsoft Office Produkte: Mehrere SchwachstellenDeutsch2026-07-14csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in verschiedenen Microsoft Office Produkten ausnutzen, um beliebigen Programmcode auszuführen, um Informationen offenzulegen, um falsche Informationen darzustellen, um seine Privilegien zu erhöhen, und um Sicherheitsvorkehrungen zu umgehen.
- msrc_CVE-2026-56164Microsoft SharePoint Server Elevation of Privilege Vulnerability2026-07-14csaf · msrc_csafUS
To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (5)
External citations — patches, advisories, analysis.
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56164cnnvd
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56164cnnvd
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56164enisa_euvd
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56164Vendor Advisorynvd
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-56164US Government Resourcenvd
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