{"id":"CVE-2026-41070","aliases":["GHSA-246w-jgmq-88fg","GO-2026-4963"],"url":"https://o3.security/vulnerability/CVE-2026-41070","summary":"openvpn-auth-oauth2 returns FUNC_SUCCESS on client-deny, allowing unauthenticated VPN access","details":"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.","published":"2026-05-08T15:14:46.186Z","modified":"2026-08-07T11:31:15.525369241Z","cvss":{"score":10,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/jkroepke/openvpn-auth-oauth2","fixedVersion":"1.27.3"}],"fix":{"url":"https://github.com/jkroepke/openvpn-auth-oauth2/commit/36f69a6c67c1054da7cbfa04ced3f0555127c8f2","label":"jkroepke/openvpn-auth-oauth2@36f69a6"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/41xxx/CVE-2026-41070.json"},{"type":"ADVISORY","url":"https://github.com/jkroepke/openvpn-auth-oauth2/security/advisories/GHSA-246w-jgmq-88fg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-41070"},{"type":"FIX","url":"https://github.com/jkroepke/openvpn-auth-oauth2/commit/36f69a6c67c1054da7cbfa04ced3f0555127c8f2"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T11:31:15.525369241Z"}}