Description
OpenVPN version 2.6.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows remote attackers to cause a denial of service via a malformed authentication token that triggers a reachable assertion when external-auth is enabled
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Openvpn | OpenVPN | 2.6.0 – ≤ 2.6.20, 2.7_alpha1 – ≤ 2.7.4 | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | openvpn | 2.7.5-1 | — |
| Debian 13 | openvpn | 2.6.14-1+deb13u3 | — |
| Debian 12 | openvpn | 2.6.14-0+deb12u2 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | openvpn | 2.7.0-1ubuntu1.2 | — |
| Ubuntu 25.10 | openvpn | No fix yet | — |
| Ubuntu 24.04 LTS | openvpn | 2.6.19-0ubuntu0.24.04.3 | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | openvpn +1 | 2.6.10-150600.3.23.1 | SUSE-SU-2026:3407-1 |
| SLES 15 SP6 | openvpn +1 | 2.6.10-150600.3.23.1 | SUSE-SU-2026:3407-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | openvpn +1 | 2.6.10-150600.3.23.1 | SUSE-SU-2026:3407-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | openvpn | 2.7.5-1.1 | openSUSE-SU-2026:11497-1 |
| openSUSE Leap 16.0 | openvpn | 2.6.10-160000.4.1 | openSUSE-SU-2026:21488-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | openvpn | 2.7.5-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | openvpn +1 | 2.6.12-1.amzn2023.0.5 | ALAS2023-2026-1990 |
Advisories 5
- WID-SEC-2026-2197 OpenVPN: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 20, 2026
- openSUSE-SU-2026:11497-1 openvpn-2.7.5-1.1 on GA media SUSE / openSUSE Security Updates · Aug 12, 2026
- openSUSE-SU-2026:21488-1 Security update for openvpn SUSE / openSUSE Security Updates · Jul 31, 2026
- SUSE-SU-2026:3407-1 Security update for openvpn SUSE / openSUSE Security Updates · Jul 30, 2026
- ALAS2023-2026-1990 Important: openvpn security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 20, 2026