SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-41070

openvpn-auth-oauth2 is a plugin/management interface client for OpenVPN server to handle an OIDC based single sign-on (SSO) auth flows.

CRITICAL 10.0EPSS 0.44%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

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.

CVSS 3.1
10.0 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
EPSS
0.44% probability · 37th percentile
CISA KEV
Not listed
Weakness
CWE-287
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.