CVE-2026-84256 Command injection in OpenVPN
Remote authenticated users can execute arbitrary commands on Windows OpenVPN servers via crafted certificate subjects.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-84256?
CVE-2026-84256 is a high-severity command injection vulnerability in OpenVPN, published on 7 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
An argument parsing issue in OpenVPN 2.1_rc10 through 2.6.22 and 2.7_alpha1 through 2.7.7 on Windows allows remote authenticated users to execute arbitrary commands via a crafted certificate subject
Which versions are affected by CVE-2026-84256?
How do I fix CVE-2026-84256?
No fix has been published for CVE-2026-84256 yet. Limit exposure of the affected software until one is available.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-84256 being exploited?
There is no known exploitation of CVE-2026-84256 in the wild and no public exploit code.
Sources
Also known as GHSA-j4fj-57fp-j5mr.