---
id: CVE-2021-34520
title: Microsoft SharePoint Server Remote Code Execution Vulnerability
summary: Microsoft SharePoint Server Remote Code Execution Vulnerability
severity: high
cvss: 8.1
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'
cwe:
  - CWE-502
vendor: microsoft
product: sharepoint_foundation
affected:
  - sharepoint_foundation = 2013
  - sharepoint_server = 2016
  - sharepoint_server = 2019
published: '2021-07-14'
updated: '2026-08-10'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-34520'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34520'
    label: secure@microsoft.com
  - url: >-
      https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34520
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.zerodayinitiative.com/advisories/ZDI-21-828/'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.04389
epssPercentile: 0.90944
zeroDay: true
ingestedAt: '2026-08-10T16:41:17.414Z'
---

## Overview

Microsoft SharePoint Server Remote Code Execution Vulnerability

## Affected

- `sharepoint_foundation = 2013`
- `sharepoint_server = 2016`
- `sharepoint_server = 2019`

## Remediation

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