CVE-2025-59228Network attack vector

Authenticated code execution via undisclosed input validation

Published Oct 14, 2025 · Updated Feb 26, 2026

Improper input validation in Microsoft SharePoint Server allows remote authenticated users to execute code over a network. Microsoft has not disclosed the affected component, accepted input, or incorrect validation operation. Low-privileged SharePoint access is required; successful exploitation grants code execution in the server's security context.

CVSS severity8.8
High
EPSS probability1.37%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in Microsoft SharePoint Server allows remote authenticated users to execute code over a network. Microsoft has not disclosed the affected component, accepted input, or incorrect validation operation. Low-privileged SharePoint access is required; successful exploitation grants code execution in the server's security context.

The record

CVE
CVE-2025-59228
Published
Oct 14, 2025
Updated
Feb 26, 2026
Vendor
Microsoft
Product
Microsoft SharePoint Enterprise Server 2016
Classifications
CWE-20, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 14, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 26, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=16.0.0 <16.0.5522.1000

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SharePoint Enterprise Server 2016version=16.0.0 <16.0.5522.1000
Microsoft · Microsoft SharePoint Server 2019version=16.0.0 <16.0.10417.20059
Microsoft · Microsoft SharePoint Server Subscription Editionversion=16.0.0 <16.0.19127.20262

Published CVSS scores

8.8Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1190Exploit Public-Facing Application

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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