CVE-2026-63649

Local arbitrary configuration loading via setenv opt

Published Aug 14, 2026 · Updated Aug 14, 2026

Improper input validation in OpenVPN for Windows 2.4.0 through 2.6.21 and 2.7_alpha1 through 2.7.5 allows local users to load configurations. The interactive service's CheckOption() allowlist validates only the option name, so --setenv opt can smuggle a nested option past validation. A local user who can reach the service control socket can escape administrator-approved configuration directories, but cannot read files beyond that user's permissions.

CVSS severity4.1
Medium
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper input validation in OpenVPN for Windows 2.4.0 through 2.6.21 and 2.7_alpha1 through 2.7.5 allows local users to load configurations. The interactive service's CheckOption() allowlist validates only the option name, so --setenv opt can smuggle a nested option past validation. A local user who can reach the service control socket can escape administrator-approved configuration directories, but cannot read files beyond that user's permissions.

The record

CVE
CVE-2026-63649
Published
Aug 14, 2026
Updated
Aug 14, 2026
Vendor
OpenVPN Inc.
Product
OpenVPN
Classifications
CWE-183
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 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=2.4.0 <2.6.22
  2. Affected versionversion=2.7_alpha1 <2.7.6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

OpenVPN Inc. · OpenVPNversion=2.4.0 <2.6.22; version=2.7_alpha1 <2.7.6

Published CVSS scores

4.1OpenVPN Inc.CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:A/VC:L/VI:N/VA:N/SC:H/SI:N/SA: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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-183Permissive List of Allowed Inputs

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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