---
id: "CVE-2026-106017"
kind: "vulnerability"
aliases: ["CVE-2026-106017"]
title: "OpenVPN 3 Core: certificate checks can be bypassed, skipping key usage restrictions"
severity: "medium"
cvss: 6.3
epss: 0.00195
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["c++", "openvpn", "package", "tls", "vpn"]
not_affected_if: ["does-not-use-openvpn-3-core"]
published_at: "2026-10-22T10:17:07+00:00"
first_seen_at: "2026-10-23T21:57:30+00:00"
updated_at: "2026-10-25T04:01:16+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-106017", "first_seen_at": "2026-10-23T21:57:30+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-106017", "first_seen_at": "2026-10-24T07:15:52+00:00"}]
---

# OpenVPN 3 Core: certificate checks can be bypassed, skipping key usage restrictions

The OpenVPN 3 Core library, versions 3.4 through 3.11.7, does not validate certificates properly. An attacker can get around extended key usage restrictions, so a certificate meant for another purpose may be accepted.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Find the OpenVPN 3 Core library version in your dependencies or build, for example in the lockfile or vendored source; unknown if the sources do not say which packages embed it.
- Check whether the version is between `3.4` and `3.11.7`.

## Fix

- Move to an OpenVPN 3 Core release newer than `3.11.7`; unknown which exact version fixes it, as the sources do not say.

## Timeline

- 2026-10-23T21:57:30+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-106017
- 2026-10-24T07:15:52+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-106017

## From the sources

Improper certificate validation in the OpenVPN 3 Core library version 3.4 through 3.11.7 allows attackers to circumvent extended key usage restrictions.

---

_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_