CVE-2026-93858 Command injection in Mistral
An authenticated user can execute arbitrary commands on the executor host via the std.ssh_proxied action in OpenStack Mistral.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-93858?
CVE-2026-93858 is a high-severity command injection vulnerability in OpenStack Mistral, published on 8 Oct 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
In OpenStack Mistral through 23.0.0, the std.ssh_proxied action passes a caller-supplied proxy_command value directly to paramiko.ProxyCommand() before any SSH connection to a gateway or target host is attempted. An authenticated project member can use the standard action-execution API to submit an arbitrary local command as proxy_command; paramiko starts that command as a subprocess on the executor host under the executor's own service account, independent of whether the SSH connection itself ever succeeds. Only Mistral deployments that permit the std.ssh_proxied action, the default configuration, are affected.
Weakness: CWE-78
Which versions are affected by CVE-2026-93858?
How do I fix CVE-2026-93858?
Apply the vendor's patch.
Upgrade, and pass arguments to programs as a list instead of through a shell. More about Command injection.
Is CVE-2026-93858 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-93858 exists.
Sources
Also known as DEBIAN-CVE-2026-93858, GHSA-gxqc-3r52-88h8, UBUNTU-CVE-2026-93858.