CVE-2026-39394
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedCI4MS 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThe Install::index() controller in CI4MS reads the 'host' POST parameter without validation and passes it to updateEnvSettings(), which writes to the .env file via preg_replace(). Because newline characters aren't stripped, an attacker can inject arbitrary configuration directives into .env, potentially achieving RCE. The InstallFilter bypass when cache('settings') is empty and disabled CSRF on install routes enable unauthenticated exploitation.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data< 0.31.4.0CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify installed Ci4ms versionLocate the version file or check composer.json, package.json, or the main application entry point for the version string. Compare against 0.31.4.0.Affected if Version is below 0.31.4.0
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Verify install route accessibilityAttempt to access the /install or /install/index route via HTTP request, or inspect route configuration files (Routes.php) to confirm install endpoints are defined and active.Affected if Install route responds or is defined in the routing configuration
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Check InstallFilter bypass conditionInspect code in the InstallFilter or security filter logic. Determine if cache('settings') returning empty can disable the filter. Check if the application initializes settings cache on startup.Affected if cache('settings') can be empty and InstallFilter is bypassed or not enforced
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Inspect .env file for injected contentOpen the .env file in the application root and scan for unexpected configuration directives, especially lines containing 'php', shell commands, or additional DATABASE_, MAIL_, or APP_ settings that were not intentionally added.Affected if The .env file contains configuration directives that were not intentionally set or contain suspicious values
A user is affected if running Ci4ms version below 0.31.4.0 with accessible install routes or empty settings cache, and the .env file shows unexpected configuration entries.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped0.31.4.0
Upgrade to CI4MS version 0.31.4.0 or later, and ensure the installation process is not accessible in production environments (remove/disable the install module after deployment).
0.31.4.0
- 1. Check the current installed version of Ci4ms by examining the composer.json or application version file
- 2. Upgrade Ci4ms to version 0.31.4.0 or later using composer update (e.g., composer require ci4ms/core:^0.31.4 or the appropriate package name)
- 3. After upgrading, verify that the Install::index() controller now properly validates/sanitizes the host POST parameter before passing it to updateEnvSettings()
- 4. Confirm the new version strips newline characters or otherwise sanitizes input before writing to the .env file
- 5. Test that the installation process still functions correctly after the upgrade
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-39394 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-39394 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data