CVE-2026-39394
HIGHDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 41% of all known CVEs.
References
Related Vulnerabilities
Other CWE-93 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2025-61884 | High | 7.5 | 98% | KEV + Ransom | - |
| CVE-2022-0666 | High | 7.5 | 44% | - | Fix |
| CVE-2016-3115 | Medium | 6.4 | 37% | - | Fix |
| CVE-2024-20337 | High | 8.2 | 30% | - | Fix |
| CVE-2021-39172 | High | 8.8 | 29% | - | Fix |
| CVE-2016-4975 | Medium | 6.1 | 20% | - | Fix |
Common questions
How do I fix CVE-2026-39394?
Upgrade ci4ms to 0.31.4.0 or later.
Is CVE-2026-39394 being actively exploited?
Not that we know of. CVE-2026-39394 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 0.52% is the estimated probability that it will be exploited in the next 30 days. That is higher than 41% of all scored CVEs.
How severe is CVE-2026-39394?
CVE-2026-39394 has a CVSS v3 base score of 8.1, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2026-39394 affect?
Published advisories record a fix for ci4ms (NVD). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
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Markdown
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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-07-24.