CVE-2026-41070 | openvpn-auth-oauth2 is a plugin/management interface client … | CVSS 10.0 CRITICAL

Description

openvpn-auth-oauth2 is a plugin/management interface client for OpenVPN server to handle an OIDC based single sign-on (SSO) auth flows. From version 1.26.3 to before version 1.27.3, when openvpn-auth-oauth2 is deployed in the experimental plugin mode (shared library loaded by OpenVPN via the plugin directive), clients that do not support WebAuth/SSO (e.g., the openvpn CLI on Linux) are incorrectly admitted to the VPN despite being denied by the authentication logic. The default management-interface mode is not affected because it does not use the OpenVPN plugin return-code mechanism. This issue has been patched in version 1.27.3.

Metadata

CVE ID: CVE-2026-41070
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-04-16 16:43 UTC
Published: 2026-05-08 15:14 UTC
Last updated: 2026-05-08 16:05 UTC
Primary CWE: CWE-287
CWE-287: Improper Authentication
Vendor / Product: jkroepke / openvpn-auth-oauth2
Sources: cve.org · NVD

Severity & Metrics

10.0 CRITICAL CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

SSVC — CISA Coordinator

Exploitation: none
Automatable: no
Tech. Impact: total

Affected products (1)

Vendor	Product	Platform	Versions
jkroepke	openvpn-auth-oauth2	—	>= 1.26.3, < 1.27.3

Weakness (CWE)

CWE	Source	Description
CWE-287	cna	CWE-287: Improper Authentication

CVSS scores (1)

Score	Severity	Version	Source	Vector
10.0	CRITICAL	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

References (2)

https://github.com/jkroepke/openvpn-auth-oauth2/security/advisories/GHSA-246w-jgmq-88fg https://github.com/jkroepke/openvpn-auth-oauth2/security/advisories/GHSA-246w-jgmq-88fg
https://github.com/jkroepke/openvpn-auth-oauth2/commit/36f69a6c67c1054da7cbfa04ced3f0555127c8f2 https://github.com/jkroepke/openvpn-auth-oauth2/commit/36f69a6c67c1054da7cbfa04ced3f0555127c8f2