---
id: "CVE-2025-49706"
kind: "vulnerability"
aliases: ["CVE-2025-49706"]
title: "Improper authentication in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a\u2026"
severity: "high"
cvss: 6.5
epss: null
exploited: true
status: "open"
category: "vendor"
products: [{"name": "Microsoft SharePoint", "fixed": [], "affected": "", "ecosystem": "vendor"}, {"name": "microsoft sharepoint enterprise server", "fixed": [], "affected": "= 2016", "ecosystem": "vendor"}, {"name": "microsoft sharepoint server", "fixed": ["16.0.18526.20424"], "affected": "< 16.0.18526.20424", "ecosystem": "vendor"}, {"name": "microsoft sharepoint server", "fixed": [], "affected": "= 2019", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "microsoft", "ransomware", "self-hosted", "sharepoint", "vendor"]
not_affected_if: ["managed-hosting", "sharepoint-online"]
published_at: "2025-07-08T17:15:58+00:00"
first_seen_at: "2026-10-23T19:11:51+00:00"
updated_at: "2026-10-23T22:29:05+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-49706", "first_seen_at": "2026-10-23T19:11:51+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-49706", "first_seen_at": "2026-10-23T22:29:05+00:00"}]
---

# Improper authentication in Microsoft Office SharePoint allows an unauthorized attacker to perform spoofing over a…

Microsoft SharePoint has an improper authentication flaw that lets an attacker who can reach the server spoof identity over the network and view sensitive information, with some changes to disclosed data possible. It is listed as exploited in the wild and tied to ransomware use, and it can be chained with CVE-2025-49704.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Microsoft SharePoint affected ? fixed ?
- vendor:microsoft sharepoint enterprise server affected = 2016 fixed ?
- vendor:microsoft sharepoint server affected < 16.0.18526.20424 fixed 16.0.18526.20424
- vendor:microsoft sharepoint server affected = 2019 fixed ?

## Fix

Apply the vendor patch for CVE-2025-49706 and the follow-up patch for CVE-2025-53771, which the sources say is more robust; disconnect end-of-life SharePoint Server versions (2013 and earlier) from the public internet.

## Timeline

- 2026-10-23T19:11:51+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2025-49706
- 2026-10-23T22:29:05+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2025-49706

## From the sources

Microsoft SharePoint contains an improper authentication vulnerability that allows an authorized attacker to perform spoofing over a network. Successfully exploitation could allow an attacker to view sensitive information and make some changes to disclosed information. This vulnerability could be chained with CVE-2025-49704. CVE-2025-53771 is a patch bypass for CVE-2025-49706, and the updates for CVE-2025-53771 include more robust protection than those for CVE-2025-49706.

CISA required action: Disconnect public-facing versions of SharePoint Server that have reached their end-of-life (EOL) or end-of-service (EOS) to include SharePoint Server 2013 and earlier versions. For supported versions, please follow the mitigations according to CISA (URL listed below in Notes) and vendor instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_