CVE-2026-64916Network attack vector

Authenticated content spoofing

Published Aug 11, 2026 · Updated Aug 25, 2026

Cross-site scripting in Microsoft SharePoint Server allows remote authenticated users to spoof content through crafted web input. Microsoft has not disclosed the vulnerable endpoint, input field, or exact rendering operation that fails to neutralize the untrusted input. Exploitation requires low-privileged authentication and victim interaction, and the published impact is limited to content disclosure or modification without a service interruption.

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

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Cross-site scripting in Microsoft SharePoint Server allows remote authenticated users to spoof content through crafted web input. Microsoft has not disclosed the vulnerable endpoint, input field, or exact rendering operation that fails to neutralize the untrusted input. Exploitation requires low-privileged authentication and victim interaction, and the published impact is limited to content disclosure or modification without a service interruption.

The record

CVE
CVE-2026-64916
Published
Aug 11, 2026
Updated
Aug 25, 2026
Vendor
Microsoft
Product
Microsoft SharePoint Enterprise Server 2016
Classifications
CWE-79, T1189
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

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

5.4NIST NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
4.6Microsoft CorporationCVSS: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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 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')
T1189Drive-by Compromise

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

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo