# 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.

- **Severity:** High 8.8 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 7 Jul 2026
- **Updated:** 7 Jul 2026
- **Also known as:** GHSA-j6j2-frv3-g6f7

## 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 (Improper Neutralization of Special Elements used in an OS Command)

## 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.

## Is CVE-2026-34158 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34158 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34158 and fix it if it is affected.

What it is: 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.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34158 exists.

Affected product: coollabsio coolify. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-34158/ (Markdown: https://insights.sbomify.com/CVE-2026-34158/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34158
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34158
- OSV: https://osv.dev/vulnerability/CVE-2026-34158

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34158/
Summaries are generated and may contain mistakes; the official description above is the record.