CVE-2026-93858 OpenStack CVE debrief

Who should care

OpenStack Mistral administrators and users who permit the std.ssh_proxied action in their deployments should assess their exposure and take steps to prevent exploitation. This includes reviewing and restricting the use of the std.ssh_proxied action, updating OpenStack Mistral to a version that fixes the vulnerability, and monitoring for suspicious activity. Additionally, security teams and vulnerability management teams should be aware of the potential for

Why it matters

CVE-2026-93858 is a high-severity vulnerability in OpenStack Mistral that allows authenticated project members to execute arbitrary local commands on the executor host. The vulnerability exists in the std.ssh_proxied action and can be exploited using the standard action-execution API. OpenStack Mistral administrators and users who permit this action should assess their exposure and take steps to prevent exploitation.

• Authenticated project members can execute arbitrary local commands on the executor host.
• Command injection can lead to privilege escalation and unauthorized access.
• The vulnerability can be exploited using the standard action-execution API.
• Verification of affected versions and remediation efforts are necessary.

Technical summary

The std.ssh_proxied action in OpenStack Mistral passes a caller-supplied proxy_command value directly to paramiko.ProxyCommand() without validation, allowing authenticated project members to execute arbitrary local commands on the executor host. This vulnerability exists in OpenStack Mistral versions 20.1.1, 21.0.1, 22.0.1, and 23.0.0, and can be exploited using the standard action-execution API. The std.ssh_proxied action is enabled by default, making deployments that permit this action vulnerable. Affected OpenStack Mistral administrators and users should assess their exposure and take steps to prevent exploitation.

Defensive priority

High

Recommended defensive actions

• Review and restrict the use of the std.ssh_proxied action in OpenStack Mistral deployments.
• Update OpenStack Mistral to a version that fixes the vulnerability, if available.
• Monitor for suspicious activity and implement compensating controls to prevent exploitation.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• Check relevant monitoring, detection, and logs for exposed assets that need extra review.
• Track exceptions, retest remediated assets, and close the item only after evidence is documented.
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up.

Evidence notes

The vulnerability is confirmed to exist in OpenStack Mistral versions 20.1.1, 21.0.1, 22.0.1, and 23.0.0. The std.ssh_proxied action is enabled by default, making deployments that permit this action vulnerable.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.