# CVE-2026-41203: CI4MS Theme::upload is vulnerable to Zip Slip leading to RCE

Source: https://junglewise.ai/threats/cve-2026-41203-ci4ms-theme-upload-is-vulnerable-to-zip-slip-leading-to-rce  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-05-07  
License: CC BY 4.0 with a link back

CVE-2026-41203 · Severity: medium · CVSS 4 · Published 2026-05-07

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.

Technologies: [ci4-cms-erp/ci4ms (Packagist)](https://junglewise.ai/threats/technologies/ci4-cms-erp-ci4ms). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2026-41203 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-41203 being exploited in the wild.

**How severe is CVE-2026-41203?** Medium severity, with a CVSS score of 4, published 7 May 2026.

**Which products and versions are affected?** ci4-cms-erp/ci4ms (Packagist) ECOSYSTEM:introduced=0,fixed=0.31.5.0.

**Is there a fix for CVE-2026-41203?** Yes. ci4-cms-erp/ci4ms (Packagist): upgrade to 0.31.5.0 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2026-41203?** Check whether you run ci4-cms-erp/ci4ms (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- ci4-cms-erp/ci4ms (Packagist): upgrade to 0.31.5.0 or later

  ```sh
  composer require ci4-cms-erp/ci4ms:^0.31.5.0
  ```


## Affected products

- ci4-cms-erp/ci4ms (Packagist) ECOSYSTEM:introduced=0,fixed=0.31.5.0

## Identifiers

- CVE-2026-41203
- GHSA-xv3r-vr59-95rg

## Related threats

- [ci4-cms-erp CI4MS stored XSS in Pages module](https://junglewise.ai/threats/cve-2026-45270-ci4-cms-erp-ci4ms-stored-xss-in-pages-module)
- [ci4-cms-erp CI4MS file deletion and rename in Fileeditor module](https://junglewise.ai/threats/cve-2026-45139-ci4-cms-erp-ci4ms-file-deletion-and-rename-in-fileeditor-module)
- [ci4-cms-erp ci4ms stored XSS in Blog and Pages content](https://junglewise.ai/threats/cve-2026-45138-ci4-cms-erp-ci4ms-stored-xss-in-blog-and-pages-content)
- [CI4MS has a Deactivated User Session Bypass (active=0)](https://junglewise.ai/threats/cve-2026-41891-ci4ms-has-a-deactivated-user-session-bypass-active-0)
- [CI4MS Vulnerable to Arbitrary Database Table Drop via Theme deleteProcess](https://junglewise.ai/threats/cve-2026-41890-ci4ms-vulnerable-to-arbitrary-database-table-drop-via-theme)