CVE-2026-41587: CI4MS: Unrestricted PHP File Upload via Theme Installation Leads to Authenticated Remote Code Execution

Severity: high (CVSS 8.6 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-07 · updated 2026-10-26
Weakness: CWE-434

Description

CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. From version 0.26.0.0 to before version 0.31.7.0, 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 inside the ZIP are installed into the web-accessible public/ directory with no extension or content filtering, making them directly executable via HTTP. This issue has been patched in version 0.31.7.0.

Affected products

ci4-cms-erp ci4ms: from 0.26.0.0, < 0.31.7.0

References

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