CVE-2026-33826

Authenticated code execution via undisclosed input validation

Published Apr 14, 2026 · Updated Apr 14, 2026

Remote code execution in Microsoft Windows Active Directory allows remote authenticated users to execute code over an adjacent network. Microsoft identifies improper input validation as the cause but has not disclosed the affected Active Directory locus or the untrusted input and operation involved. A low-privilege account and adjacent-network access are required; successful exploitation executes attacker-controlled code on the affected server.

CVSS severity8.0
High
EPSS probability0.53%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Remote code execution in Microsoft Windows Active Directory allows remote authenticated users to execute code over an adjacent network. Microsoft identifies improper input validation as the cause but has not disclosed the affected Active Directory locus or the untrusted input and operation involved. A low-privilege account and adjacent-network access are required; successful exploitation executes attacker-controlled code on the affected server.

The record

CVE
CVE-2026-33826
Published
Apr 14, 2026
Updated
Apr 14, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-20, T1210
Attack vector
adjacent
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 14, 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=10.0.17763.0 <10.0.17763.8644

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.8644
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.32690
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.9060
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.2274
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.9060
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.23132
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.8644
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.5020
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.32690
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.23132

Published CVSS scores

8.0Microsoft CorporationCVSS:3.1/AV:A/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)
Vectoradjacent
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1210Exploitation of Remote Services

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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