CVE-2026-39394 CI4MS has an .env CRLF Injection via Unvalidated `host` Parameter in Install Controller
Attackers can inject arbitrary configuration directives into the .env file via the install controller, potentially leading to code execution or security bypasses.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-39394?
CVE-2026-39394 is a high-severity vulnerability in ci4-cms-erp ci4ms, published on 8 Apr 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to 0.31.4.0, the Install::index() controller reads the host POST parameter without any validation and passes it directly into updateEnvSettings(), which writes it into the .env file via preg_replace(). Because newline characters in the value are not stripped, an attacker can inject arbitrary configuration directives into the .env file. The install routes have CSRF protection explicitly disabled, and the InstallFilter can be bypassed when cache('settings') is empty (cache expiry or fresh deployment). This vulnerability is fixed in 0.31.4.0.
Weakness: CWE-93
Which versions are affected by CVE-2026-39394?
2 open source packages ship an affected version, including ci4-cms-erp/ci4ms. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
ci4-cms-erp/ci4ms Packagist | All versions | 0.31.4.0 |
ci4-cms-erp/ci4ms Packagist | All versions | 0.31.4.0 |
Products include Ci4-Cms-Erp Ci4ms.
How do I fix CVE-2026-39394?
Upgrade ci4-cms-erp/ci4ms to 0.31.4.0 or later.
Is CVE-2026-39394 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-39394 exists.
Other vulnerabilities in ci4-cms-erp ci4ms
- CVE-2026-34569 CI4MS: Blogs Categories Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS
- CVE-2026-34571 CI4MS: Stored Cross‑Site Scripting (Stored XSS) in Backend User Management Allows Session Hijacking and Full Administrative Account Compromise
- CVE-2026-25510 CI4MS Vulnerable to Remote Code Execution (RCE) via Arbitrary File Creation and Save in File Editor
- CVE-2026-34989 CI4MS: Profile & User Management Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS
- CVE-2026-34559 CI4MS: Blogs Tags Full Account Takeover for All-Roles & Privilege-Escalation via Stored DOM XSS
Sources
Also known as GHSA-vfhx-5459-qhqh.