---
id: CVE-2026-58644
title: >-
  Deserialization of untrusted data in Microsoft Office SharePoint allows an
  unauthorized attacker to execute code over a network.
summary: >-
  Deserialization of untrusted data in Microsoft Office SharePoint allows an
  unauthorized attacker to execute code over a network.
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-502
vendor: microsoft
product: sharepoint_server
affected:
  - sharepoint_server < 16.0.19725.20434
  - sharepoint_server = 2016
  - sharepoint_server = 2019
patched:
  - sharepoint_server 16.0.19725.20434
published: '2026-07-14'
updated: '2026-07-17'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-58644'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-58644'
    label: secure@microsoft.com
  - url: >-
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-58644
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - kev
  - in-the-wild
  - exploit-available
  - cve.org
epss: 0.60944
epssPercentile: 0.99114
kev: true
kevDateAdded: '2026-07-16'
kevDueDate: '2026-07-19'
kevRansomware: false
exploited: true
ingestedAt: '2026-07-17T20:15:42.997Z'
exploits:
  nuclei:
    - CVE-2026-58644
  checkedAt: '2026-09-24T07:53:09.615Z'
exploitAvailable: true
ssvc:
  exploitation: active
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-07-16T00:00:00+00:00'
---

## Overview

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

## Affected

- `sharepoint_server < 16.0.19725.20434`
- `sharepoint_server = 2016`
- `sharepoint_server = 2019`

## Remediation

Upgrade past the affected range:

- `sharepoint_server 16.0.19725.20434`