dbcve.org
Path TraversalWeakness · CWE-22

CVE-2026-41203

CRITICAL · 9.4 CVSS v4.0 Published 2026-05-07
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable Zero-click

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 · unedited
CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to version 0.31.5.0, ci4ms Theme::upload extracts user uploaded ZIP archives without validating entry names, allowing an authenticated backend user with the theme create permission to write files to arbitrary filesystem locations (Zip Slip) and achieve remote code execution by dropping a PHP file under the public web root. This issue has been patched in version 0.31.5.0.

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 confidence

CI4MS Theme::upload function extracts user-uploaded ZIP archives without validating entry names, allowing path traversal (Zip Slip). An authenticated backend user with theme create permission can write files to arbitrary locations and achieve RCE by placing PHP files in the web root.

MitigationUpgrade to version 0.31.5.0 or later which includes proper path validation for ZIP entries.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS 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
Low
Authentication
X
User interaction
None
Scope
X

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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 checks

Work through these to decide whether this CVE applies to you.

  1. Locate CI4MS installation
    Identify the CI4MS application directory on the server. Look for files containing the Theme class or theme-related controllers (e.g., theme.php, Theme.php, or controllers handling /theme/* routes).
    Affected if CI4MS is present and the Theme::upload function exists in the codebase
  2. Determine CI4MS version
    Check version.php, composer.json, or any version file in the CI4MS root for the installed version number. Compare it to 0.31.5.0.
    Affected if Installed version is lower than 0.31.5.0 or the version cannot be determined (vulnerable if unpatched)
  3. Verify theme upload functionality is present
    Search for the upload method in the Theme class (look for function upload() or similar). Confirm the method exists and handles ZIP file extraction.
    Affected if Theme::upload function exists and performs ZIP extraction without visible path validation (e.g., no check for '../' or absolute paths in entry names)
  4. Check user permission configuration
    Examine the authentication and authorization system for theme create/upload permissions. Look for permission checks like 'theme.create', 'theme.upload', or role-based access controls in the user management module.
    Affected if Backend users can be granted theme create permission and the permission check is present in the upload flow
  5. Confirm web root is writable by the application
    Verify the web server document root directory permissions. Check if the application process has write access to the web-accessible directory where uploaded files are extracted.
    Affected if The application can write extracted files to a location reachable via HTTP (web root or subdirectories thereof)

The environment is affected if CI4MS is installed with a version prior to 0.31.5.0, the Theme::upload function performs ZIP extraction, and authenticated users with theme create permissions can write files to a web-accessible directory.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to version 0.31.5.0 or later which includes proper path validation for ZIP entries.

Recommended fix High confidence

0.31.5.0

  1. 1. Back up your current CI4MS installation before making any changes.
  2. 2. Download version 0.31.5.0 or later from the official CI4MS repository.
  3. 3. Replace the existing installation files with the new version, preserving your configuration and data files.
  4. 4. Verify that the Theme::upload method now validates entry names in ZIP archives before extraction.
  5. 5. Test the theme upload functionality to confirm the patch is working correctly.
  6. 6. Ensure that only trusted users with proper permissions have access to the theme upload feature.
Caveat Review release notes for any configuration or database changes between your current version and 0.31.5.0

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,930
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-41203 in production — separate from our analysis above.

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What this is

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.

What belongs here
  • 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