---
id: CVE-2026-56164
title: Microsoft SharePoint Server Elevation of Privilege Vulnerability
summary: >-
  Missing authentication for critical function in Microsoft Office SharePoint
  allows an unauthorized attacker to elevate privileges over a network.
severity: medium
cvss: 5.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:F/RL:O/RC:C'
cvssSource: cna
cwe:
  - CWE-306
vendor: Microsoft
product: Microsoft SharePoint Enterprise Server 2016
affected:
  - sharepoint_enterprise_server_2016 >= 16.0.0 < 16.0.5561.1001
  - sharepoint_server_2019 >= 16.0.0 < 16.0.10417.20175
  - sharepoint_server_subscription_edition >= 16.0.0 < 16.0.19725.20434
ssvc:
  exploitation: active
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-07-14T18:45:11.388695Z'
exploited: true
exploitAvailable: true
published: '2026-07-14'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T22:29:12.623Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-56164'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56164'
    label: Microsoft SharePoint Server Elevation of Privilege Vulnerability
tags:
  - cve.org
  - in-the-wild
  - exploit-available
  - kev
epss: 0.26636
epssPercentile: 0.97975
kev: true
kevDateAdded: '2026-07-14'
kevDueDate: '2026-07-17'
kevRansomware: false
exploits:
  github: 2
  githubRepos:
    - 'https://github.com/sentinel-aidefense/CVE-2026-56164-EXP'
    - 'https://github.com/sam00/POC-CVE-2026-56164-exploit'
  checkedAt: '2026-09-21T15:29:41.191Z'
zeroDay: true
ingestedAt: '2026-09-08T17:06:31.928Z'
---

## Overview

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

## Affected

- `sharepoint_enterprise_server_2016 >= 16.0.0 < 16.0.5561.1001`
- `sharepoint_server_2019 >= 16.0.0 < 16.0.10417.20175`
- `sharepoint_server_subscription_edition >= 16.0.0 < 16.0.19725.20434`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.