CVE-2025-20387

Local file access via incorrect directory ACLs

Published Dec 3, 2025 · Updated Feb 26, 2026

Improper permissions in Splunk Universal Forwarder for Windows allow local users to access installation files after installation or upgrade. The installer leaves ACL grants for BUILTIN Users and Authenticated Users on the installation tree instead of restricting the security-critical resource. Exploitation requires local non-administrator access and an affected installation or upgrade; every file under the directory becomes accessible.

CVSS severity8.0
High
EPSS probability0.49%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper permissions in Splunk Universal Forwarder for Windows allow local users to access installation files after installation or upgrade. The installer leaves ACL grants for BUILTIN Users and Authenticated Users on the installation tree instead of restricting the security-critical resource. Exploitation requires local non-administrator access and an affected installation or upgrade; every file under the directory becomes accessible.

The record

CVE
CVE-2025-20387
Published
Dec 3, 2025
Updated
Feb 26, 2026
Vendor
Splunk, Inc.
Product
Splunk Enterprise
Classifications
CWE-732, T1005
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 3, 2025CVE publishedPublication date reported by the CVE source.
  2. Feb 26, 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 <10.0.2
  2. Affected versionversion=9.2 <9.2.10
  3. Affected versionversion=9.3 <9.3.8
  4. Affected versionversion=9.4 <9.4.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Splunk, Inc. · Splunk Enterpriseversion=10.0 <10.0.2; version=9.2 <9.2.10; version=9.3 <9.3.8; version=9.4 <9.4.6

Published CVSS scores

8.0SplunkCVSS:3.1/AV:N/AC:L/PR:L/UI:R/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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-732Incorrect Permission Assignment for Critical Resource
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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