Ci4Ms · Ci4Ms · CVE-2026-41587
**Name of the Vulnerable Software and Affected Versions**
CI4MS versions 0.26.0.0 through 0.31.6.0
**Description**
A theme upload feature allows any authenticated backend user with theme-upload permission to achieve remote code execution (RCE) by uploading a crafted ZIP file. PHP files within the ZIP are installed into the web-accessible `public/` directory without extension or content filtering, making them directly executable via HTTP. The issue occurs because the `install theme from tmp()` function is called unconditionally, and the helper function in `modules/Theme/Helpers/themes helper.php` copies files using `rename()` without an allowlist, MIME check, or content inspection. Specifically, the endpoint '/backend/themes/upload' is used to upload the file, and the theme name is derived from the filename. Files are also installed without filtering into `app/Controllers/templates/`, `app/Libraries/templates/`, and other `app/` subdirectories.
**Recommendations**
Update to version 0.31.7.0.
As a temporary workaround, restrict access to the '/backend/themes/upload' endpoint or revoke theme-upload permissions for non-administrative users.