---
id: CVE-2025-53770
title: >-
  Deserialization of untrusted data in on-premises Microsoft SharePoint Server
  allows an unauthorized attacker to execute code over a network.

  Microsoft is aware that an exploit for CVE-2025-53770 exists in the wild.

  Microsoft is preparing…
summary: >-
  Deserialization of untrusted data in on-premises Microsoft SharePoint Server
  allows an unauthorized attacker to execute code over a network.

  Microsoft is aware that an exploit for CVE-2025-53770 exists in the wild.

  Microsoft is preparing…
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 < 16.0.18526.20508
  - sharepoint_server = 2016
  - sharepoint_server = 2019
patched:
  - sharepoint_server 16.0.18526.20508
published: '2025-07-20'
updated: '2026-08-04'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-53770'
references:
  - url: 'https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53770'
    label: secure@microsoft.com
  - url: >-
      https://arstechnica.com/security/2025/07/sharepoint-vulnerability-with-9-8-severity-rating-is-under-exploit-across-the-globe/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://github.com/kaizensecurity/CVE-2025-53770'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://msrc.microsoft.com/blog/2025/07/customer-guidance-for-sharepoint-vulnerability-cve-2025-53770/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://news.ycombinator.com/item?id=44629710'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://research.eye.security/sharepoint-under-siege/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://therecord.media/microsoft-sharepoint-zero-day-vulnerability-exploited-globally
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.bleepingcomputer.com/news/microsoft/microsoft-sharepoint-zero-day-exploited-in-rce-attacks-no-patch-available/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.cisa.gov/news-events/alerts/2025/07/20/microsoft-releases-guidance-exploitation-sharepoint-vulnerability-cve-2025-53770
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.darkreading.com/remote-workforce/microsoft-rushes-emergency-fix-exploited-sharepoint-toolshell-flaw
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.forbes.com/sites/daveywinder/2025/07/20/microsoft-confirms-ongoing-mass-sharepoint-attack---no-patch-available/
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://x.com/Shadowserver/status/1946900837306868163'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: >-
      https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-53770
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - kev
  - in-the-wild
  - exploit-available
epss: 0.99998
epssPercentile: 0.99991
kev: true
kevDateAdded: '2025-07-20'
kevDueDate: '2025-07-21'
kevRansomware: true
exploited: true
exploitAvailable: true
zeroDay: true
ingestedAt: '2026-08-04T05:36:13.285Z'
exploits:
  exploitdb: true
  github: 44
  githubRepos:
    - 'https://github.com/RukshanaAlikhan/CVE-2025-53770'
    - >-
      https://github.com/Bluefire-Redteam-Cybersecurity/bluefire-sharepoint-cve-2025-53770
    - 'https://github.com/kaizensecurity/CVE-2025-53770'
  metasploit:
    - exploit/windows/http/sharepoint_toolpane_rce
  nuclei:
    - CVE-2025-53770
  checkedAt: '2026-09-10T03:03:49.947Z'
---

## Overview

Deserialization of untrusted data in on-premises Microsoft SharePoint Server allows an unauthorized attacker to execute code over a network.
Microsoft is aware that an exploit for CVE-2025-53770 exists in the wild.
Microsoft is preparing and fully testing a comprehensive update to address this vulnerability.  In the meantime, please make sure that the mitigation provided in this CVE documentation is in place so that you are protected from exploitation.

## Affected

- `sharepoint_server < 16.0.18526.20508`
- `sharepoint_server = 2016`
- `sharepoint_server = 2019`

## Remediation

Upgrade past the affected range:

- `sharepoint_server 16.0.18526.20508`