CVE-2025-27738Network attack vector

File-path disclosure via unchecked change notifications

Published Apr 8, 2025 · Updated Aug 10, 2026

Improper access control in Microsoft Windows ReFS allows remote authenticated users to disclose protected file paths over a network. Directory change notifications report a changed file or folder's full path without first checking FILE_LIST_DIRECTORY access on its parent folder. The user must hold network-accessible credentials and monitor a permitted parent directory; the flaw exposes path names, not file contents.

CVSS severity6.5
Medium
EPSS probability3.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper access control in Microsoft Windows ReFS allows remote authenticated users to disclose protected file paths over a network. Directory change notifications report a changed file or folder's full path without first checking FILE_LIST_DIRECTORY access on its parent folder. The user must hold network-accessible credentials and monitor a permitted parent directory; the flaw exposes path names, not file contents.

The record

CVE
CVE-2025-27738
Published
Apr 8, 2025
Updated
Aug 10, 2026
Vendor
Microsoft
Product
Windows 10 Version 1507
Classifications
CWE-284, T1083
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Apr 8, 2025CVE publishedPublication date reported by the CVE source.
  2. Aug 10, 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=10.0.10240.0 <10.0.10240.20978

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Microsoft · Windows 10 Version 1507version=10.0.10240.0 <10.0.10240.20978
Microsoft · Windows Server 2019version=10.0.17763.0 <10.0.17763.7136
Microsoft · Windows Server 2025 (Server Core installation)version=10.0.26100.0 <10.0.26100.3775
Microsoft · Windows Server 2016 (Server Core installation)version=10.0.14393.0 <10.0.14393.7969
Microsoft · Windows 11, version 24H2version=10.0.26100.0 <10.0.26100.3775
Microsoft · Windows Server 2012 (Server Core installation)version=6.2.9200.0 <6.2.9200.25423
Microsoft · Windows Server 2012version=6.2.9200.0 <6.2.9200.25423
Microsoft · Windows 10 Version 21H2version=10.0.19044.0 <10.0.19044.5737
Microsoft · Windows Server 2022, 23H2 Edition (Server Core installation)version=10.0.25398.0 <10.0.25398.1551
Microsoft · Windows Server 2016version=10.0.14393.0 <10.0.14393.7969
Microsoft · Windows 11 Version 22H3version=10.0.22631.0 <10.0.22631.5189
Microsoft · Windows 10 Version 22H2version=10.0.19045.0 <10.0.19045.5737
Microsoft · Windows Server 2012 R2 (Server Core installation)version=6.3.9600.0 <6.3.9600.22523
Microsoft · Windows Server 2019 (Server Core installation)version=10.0.17763.0 <10.0.17763.7136
Microsoft · Windows 11 Version 23H2version=10.0.22631.0 <10.0.22631.5189
Microsoft · Windows 11, version 22H2version=10.0.22621.0 <10.0.22621.5189
Microsoft · Windows 10 Version 1607version=10.0.14393.0 <10.0.14393.7969
Microsoft · Windows Server 2022version=10.0.20348.0 <10.0.20348.3453
Microsoft · Windows Server 2025version=10.0.26100.0 <10.0.26100.3775
Microsoft · Windows 10 Version 1809version=10.0.17763.0 <10.0.17763.7136
Microsoft · Windows Server 2012 R2version=6.3.9600.0 <6.3.9600.22523

Published CVSS scores

6.5Microsoft CorporationCVSS:3.1/AV:N/AC:L/PR:L/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)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-284Improper Access Control
T1083File and Directory Discovery

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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