CVE-2026-41070 json
openvpn-auth-oauth2 returns FUNC_SUCCESS on client-deny, allowing unauthenticated VPN access
published 6mo ago modified 14d ago also GHSA-246w-jgmq-88fg , GO-2026-4963 , EUVD-2026-28789
- cvss
- 10.0
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.4%
- EPSS 0.4% chance of exploitation in 30 days, percentile 38%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go github.com/jkroepke/openvpn-auth-oauth2 1.27.3
- openvpn-auth-oauth2 Debian 14 1.27.3-1
debian advisories DEBIAN-CVE-2026-41070
- govulncheck-vulndb openSUSE Leap 16.0 0.0.20260723T184607-160000.1.1
opensuse advisories openSUSE-SU-2026:21483-1
Is CVE-2026-41070 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
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- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 6mo ago
Exploit prediction
0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N |
| GitHub | 3.1 | 10.0 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | github.com/jkroepke/openvpn-auth-oauth2 | >=1.26.3, <1.27.3 |
1.27.3 |
Affected products
- jkroepke openvpn-auth-oauth2
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
github.com
/jkroepke/openvpn-auth-oauth2/commit/36f69a6c67c1054da7cbfa04ced3f0555127c8f2
web, patch
-
github.com
/jkroepke/openvpn-auth-oauth2/pull/829
web, patch
-
github.com
/jkroepke/openvpn-auth-oauth2/security/advisories/GHSA-246w-jgmq-88fg
web, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2026-41070
advisory
-
github.com
/OpenVPN/openvpn/blob/master/include/openvpn-plugin.h.in
web
-
github.com
/OpenVPN/openvpn3/blob/master/doc/webauth.md
web
-
github.com
/jkroepke/openvpn-auth-oauth2
package
-
github.com
/jkroepke/openvpn-auth-oauth2/releases/tag/v1.27.3
web
Sources
- CVE List CVE-2026-41070
- GitHub Advisory GHSA-246w-jgmq-88fg
- NVD CVE-2026-41070
- OSV GO-2026-4963
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