CVE-2026-34158 Coolify: Command injection via single-quote breakout in Docker Compose custom commands
Attackers can inject commands into Docker Compose settings to execute arbitrary code on the host server, bypassing container isolation.
- 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-2026-34158?
CVE-2026-34158 is a high-severity command injection vulnerability in coollabsio coolify, published on 7 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Prior to 4.0.0-beta.469, the executeInDocker() helper wraps user-controlled commands in single quotes without escaping embedded single quotes. Attackers who can edit application settings can inject a single quote into docker_compose_custom_build_command or docker_compose_custom_start_command to break out of the quoted context and execute arbitrary commands on the managed server host during deployments, escaping the intended Docker container confinement. This issue is fixed in version 4.0.0-beta.469.
Weakness: CWE-78
Which versions are affected by CVE-2026-34158?
How do I fix CVE-2026-34158?
No fix has been published for CVE-2026-34158 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-2026-34158 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34158 exists.
Sources
Also known as GHSA-j6j2-frv3-g6f7.