Description
Retransmissions of ACK packet ID in OpenVPN through 2.6.22 and 2.7.6 allow remote unauthenticated attackers to cause a denial of service via crafted inputs that trigger a timeout integer overflow
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| OpenVPN | OpenVPN | ≤ 2.6.22, ≤ 2.7.6 | — |
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 | 2.7.7-1 | — |
| Debian 13 | openvpn | No fix yet | — |
| Debian 12 | openvpn | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | openvpn | 2.7.0-1ubuntu1.3 | USN-8852-1 |
| Ubuntu 24.04 LTS | openvpn | 2.6.19-0ubuntu0.24.04.4 | USN-8852-1 |
| Ubuntu 22.04 LTS | openvpn | 2.5.11-0ubuntu0.22.04.5 | USN-8852-1 |
| Ubuntu 20.04 LTS | openvpn | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 18.04 LTS | openvpn | No fix yet | — |
| Ubuntu Pro 16.04 LTS | openvpn | No fix yet | — |
| Ubuntu Pro 14.04 LTS | openvpn | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | openvpn +1 | 2.6.10-150600.3.37.1 | SUSE-SU-2026:4213-1 |
| SLES 15 SP6 | openvpn +1 | 2.6.10-150600.3.37.1 | SUSE-SU-2026:4213-1 |
| SLES 15 SP5 | openvpn | 2.5.6-150400.3.28.1 | SUSE-SU-2026:4217-1 |
| SLES 15 SP4 | openvpn | 2.5.6-150400.3.28.1 | SUSE-SU-2026:4217-1 |
| SLES 12 SP5 | openvpn | 2.3.8-16.38.1 | SUSE-SU-2026:4242-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | openvpn | 2.6.10-160000.5.1 | SUSE-SU-2026:24220-1 |
| SLES for SAP 15 SP6 | openvpn +1 | 2.6.10-150600.3.37.1 | SUSE-SU-2026:4213-1 |
| SLES for SAP 15 SP5 | openvpn | 2.5.6-150400.3.28.1 | SUSE-SU-2026:4217-1 |
| SLES for SAP 15 SP4 | openvpn | 2.5.6-150400.3.28.1 | SUSE-SU-2026:4217-1 |
| SLES 16.0 | openvpn | 2.6.10-160000.5.1 | SUSE-SU-2026:24220-1 |
| SLE HPC 15 SP5 | openvpn | 2.5.6-150400.3.28.1 | SUSE-SU-2026:4217-1 |
| SLE HPC 15 SP4 | openvpn | 2.5.6-150400.3.28.1 | SUSE-SU-2026:4217-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | openvpn | 2.6.10-160000.5.1 | openSUSE-SU-2026:22072-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | openvpn | 2.7.7-r0 | — |
Advisories 7
- SUSE-SU-2026:24220-1 Security update for openvpn SUSE / openSUSE Security Updates · Oct 21, 2026
- WID-SEC-2026-3202 OpenVPN: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 20, 2026
- openSUSE-SU-2026:22072-1 Security update for openvpn SUSE / openSUSE Security Updates · Oct 19, 2026
- USN-8852-1 openvpn vulnerabilities Ubuntu Security Notices (USN) · Oct 17, 2026
- SUSE-SU-2026:4242-1 Security update for openvpn SUSE / openSUSE Security Updates · Sep 17, 2026
- SUSE-SU-2026:4217-1 Security update for openvpn SUSE / openSUSE Security Updates · Sep 17, 2026
- SUSE-SU-2026:4213-1 Security update for openvpn SUSE / openSUSE Security Updates · Sep 16, 2026