CVE-2026-26114Network attack vector

Authenticated code execution via unsafe deserialization

Published Mar 10, 2026 · Updated Mar 10, 2026

Deserialization of untrusted data in affected Microsoft SharePoint Server 2016 and 2019 builds allows remote authenticated users to execute code. Microsoft has not disclosed the affected SharePoint component, serialized-data format, or deserialization operation that accepts attacker-controlled data. A low-privileged authenticated account can reach the flaw over the network and execute code with the vulnerable service's privileges.

CVSS severity8.8
High
EPSS probability3.03%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Deserialization of untrusted data in affected Microsoft SharePoint Server 2016 and 2019 builds allows remote authenticated users to execute code. Microsoft has not disclosed the affected SharePoint component, serialized-data format, or deserialization operation that accepts attacker-controlled data. A low-privileged authenticated account can reach the flaw over the network and execute code with the vulnerable service's privileges.

The record

CVE
CVE-2026-26114
Published
Mar 10, 2026
Updated
Mar 10, 2026
Vendor
Microsoft
Product
Microsoft SharePoint Enterprise Server 2016
Classifications
CWE-502, T1190
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 10, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 10, 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 <16.0.5543.1000

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Microsoft SharePoint Enterprise Server 2016version=16.0.0 <16.0.5543.1000
Microsoft · Microsoft SharePoint Server 2019version=16.0.0 <16.0.10417.20102

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-502Deserialization of Untrusted Data
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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