CVE-2026-20818Hinoki check available

Local information disclosure via sensitive log insertion

Published Jan 13, 2026 · Updated Jan 13, 2026

Sensitive log exposure in affected Windows Server 2016, 2019, 2022, 23H2, and 2025 builds allows local users to read protected data. The Windows Kernel writes sensitive information to an unspecified log file, but Microsoft has not identified the log, data, or triggering operation. No privileges or user interaction are required beyond local execution, and the reported consequence is limited to information disclosure.

CVSS severity6.2
Medium
EPSS probability0.73%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Sensitive log exposure in affected Windows Server 2016, 2019, 2022, 23H2, and 2025 builds allows local users to read protected data. The Windows Kernel writes sensitive information to an unspecified log file, but Microsoft has not identified the log, data, or triggering operation. No privileges or user interaction are required beyond local execution, and the reported consequence is limited to information disclosure.

The record

CVE
CVE-2026-20818
Published
Jan 13, 2026
Updated
Jan 13, 2026
Vendor
Microsoft
Product
Windows Server 2019
Classifications
CWE-532, T1005
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 13, 2026CVE publishedPublication date reported by the CVE source.
  2. Jan 13, 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 <10.0.17763.8276

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.8276
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.7623
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.8783
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.2092
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.8783
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.8276
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.4648
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.7623

Published CVSS scores

6.2Microsoft CorporationCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/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)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-532Insertion of Sensitive Information into Log File
T1005Data from Local System

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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