# CVE-2026-34234: CtrlPanel: Unauthenticated RCE using installer script

> Unauthenticated attackers can execute arbitrary commands on CtrlPanel servers via the installer script due to missing lock checks and unsanitized input.

- **Severity:** Critical 10.0 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 19 May 2026
- **Updated:** 20 May 2026
- **Also known as:** GHSA-jmhr-q9q5-fqwh

## What is CVE-2026-34234?

CVE-2026-34234 is a critical command injection vulnerability in Ctrlpanel-gg panel, published on 19 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

CtrlPanel is open-source billing software for hosting providers. In versions 1.1.1 and prior, the web-based installer (public/installer/index.php) is vulnerable to unauthenticated Remote Code Execution (RCE) because it performs the install.lock check only after including and executing form handler files, leaving installer endpoints reachable on already-installed instances. The handlers also pass unsanitized user input directly into shell commands, allowing an attacker to submit crafted requests that execute arbitrary commands on the server. The vulnerability stems from two combined weaknesses: (1) premature form handler execution before the lock file gate, and (2) unsafe use of user input in shell command construction. This issue is reported to be actively exploited in the wild. The issue has been fixed in version 1.2.0.

Weakness: CWE-78 (Improper Neutralization of Special Elements used in an OS Command), CWE-284 (Improper Access Control)

## Which versions are affected by CVE-2026-34234?


## How do I fix CVE-2026-34234?

No fix has been published for CVE-2026-34234 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-34234 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34234 exists.

Public exploit code:

- https://github.com/rootdirective-sec/CVE-2026-34234-Lab (github_poc): https://github.com/rootdirective-sec/CVE-2026-34234-Lab
- CtrlPanel <= 1.1.1 - Remote Code Execution (nuclei): http/cves/2026/CVE-2026-34234.yaml

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-34234 and fix it if it is affected.

What it is: CVE-2026-34234 is a critical command injection vulnerability in Ctrlpanel-gg panel, published on 19 May 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-34234 exists.

Affected product: Ctrlpanel-gg panel. 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-2026-34234/ (Markdown: https://insights.sbomify.com/CVE-2026-34234/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-34234
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-34234
- OSV: https://osv.dev/vulnerability/CVE-2026-34234

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-34234/
Summaries are generated and may contain mistakes; the official description above is the record.