CVE-2026-64902Network attack vector

Authenticated content spoofing via unneutralized web input

Published Aug 11, 2026 · Updated Aug 25, 2026

Cross-site scripting in Microsoft SharePoint Server 16.0.0 allows remote authenticated users to spoof content over a network. During web-page generation, SharePoint fails to neutralize attacker-controlled input before including it in browser-rendered output; Microsoft has not disclosed the affected page, field, or routine. Exploitation requires SharePoint authorization and user interaction, and the documented impact is limited to confidentiality and integrity effects with no service interruption.

CVSS severity4.6
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Cross-site scripting in Microsoft SharePoint Server 16.0.0 allows remote authenticated users to spoof content over a network. During web-page generation, SharePoint fails to neutralize attacker-controlled input before including it in browser-rendered output; Microsoft has not disclosed the affected page, field, or routine. Exploitation requires SharePoint authorization and user interaction, and the documented impact is limited to confidentiality and integrity effects with no service interruption.

The record

CVE
CVE-2026-64902
Published
Aug 11, 2026
Updated
Aug 25, 2026
Vendor
Microsoft
Product
Microsoft SharePoint Enterprise Server 2016
Classifications
CWE-79, CAPEC-63, T1059.007
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 11, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 25, 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 <16.0.5565.1001

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SharePoint Enterprise Server 2016version=16.0.0 <16.0.5565.1001
Microsoft · Microsoft SharePoint Server 2019version=16.0.0 <16.0.10417.20198
Microsoft · Microsoft SharePoint Server Subscription Editionversion=16.0.0 <16.0.19725.20522

Published CVSS scores

5.4NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
4.6MicrosoftCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

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-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CAPEC-63Cross-Site Scripting (XSS)
T1059.007JavaScript/JScript

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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