OpenVPN 2.5.0 through 2.7.6 on Windows using the tap-windows6 driver allows attackers to trigger an out-of-bounds write via crafted DOMAIN-SEARCH entries

Attack Vector Network

Attack Complexity High

Privileges Required None

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact Low

Subsequent System Availability Impact Low

Attack Vector Network

Attack Complexity High

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact Low

Availability Impact Low

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00331.

Exploitation none

Automatable no

Technical Impact partial

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
OpenVPN OpenVPN unaffected
Version Status Constraints
2.5.0 affected ≤ 2.7.6

No data.

No data.

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Vendors Products
Openvpn Subscribe
Openvpn Subscribe

Project Subscriptions

Vendors Products
Openvpn Subscribe
Openvpn Subscribe
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://community.openvpn.net/Security%20Announcements/CVE-2026-81738 cve-icon cve-icon cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-81738 cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-81738 cve-icon
History

Tue, 08 Sep 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Tue, 08 Sep 2026 00:15:00 +0000

Type Values Removed Values Added
Title OpenVPN Windows TAP-Windows6 Out-of-Bounds Write via DOMAIN-SEARCH entries openvpn: OpenVPN: Out-of-bounds write via crafted DOMAIN-SEARCH entries
References
Metrics threat_severity

None

 cvssV3_1

{'score': 4.2, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L'}

threat_severity

Low

Mon, 07 Sep 2026 16:00:00 +0000

Type Values Removed Values Added
Title OpenVPN Windows TAP-Windows6 Out-of-Bounds Write via DOMAIN-SEARCH entries

Mon, 07 Sep 2026 15:15:00 +0000

Type Values Removed Values Added
First Time appeared Openvpn
Openvpn openvpn
Vendors & Products Openvpn
Openvpn openvpn

Mon, 07 Sep 2026 08:00:00 +0000

Type Values Removed Values Added
Description OpenVPN 2.5.0 through 2.7.6 on Windows using the tap-windows6 driver allows attackers to trigger an out-of-bounds write via crafted DOMAIN-SEARCH entries
Weaknesses CWE-121
CWE-193
CWE-787
References
Metrics cvssV4_0

{'score': 2.3, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:L/SA:L'}

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: OpenVPN

Published:

Updated: 2026-09-08T14:55:10.107Z

Reserved: 2026-08-27T11:45:58.319Z

Link: CVE-2026-81738

cve-icon Vulnrichment

Updated: 2026-09-08T14:55:04.969Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-09-07T08:17:13.270

Modified: 2026-09-08T19:07:52.113

Link: CVE-2026-81738

cve-icon Redhat

Severity : Low

Publid Date: 2026-09-07T07:32:20Z

Links: CVE-2026-81738 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-09-07T15:45:17Z

Weaknesses