CVE-2026-41890 Overview
CVE-2026-41890 is an input validation vulnerability [CWE-20] in CI4MS, a CodeIgniter 4-based content management system skeleton. The flaw exists in the theme deletion workflow between versions 0.31.1.0 and 0.31.8.0. The deleteProcess() action accepts a tables[] POST parameter and forwards values directly to $forge->dropTable() without validating them against the theme's migration files. An authenticated administrator can submit arbitrary table names and drop any table in the application database. The maintainers patched the issue in version 0.31.8.0.
Critical Impact
An authenticated admin can destroy arbitrary database tables, causing data loss and full application unavailability across CI4MS deployments running affected versions.
Affected Products
- CI4MS versions 0.31.1.0 through 0.31.7.x
- CodeIgniter 4-based deployments using the CI4MS skeleton
- Modular CMS instances built on CI4MS with RBAC and theme management enabled
Discovery Timeline
- 2026-05-07 - CVE-2026-41890 published to NVD
- 2026-05-07 - Last updated in NVD database
Technical Details for CVE-2026-41890
Vulnerability Analysis
CI4MS exposes a theme deletion feature that removes a theme along with the database tables it created during installation. The deleteConfirm view correctly enumerates the tables associated with a specific theme by reading that theme's migration files. The view then renders these table names as tables[] form values for confirmation.
The server-side deleteProcess() handler trusts the submitted tables[] array without re-deriving the legitimate table list from the theme's migration files. Each value in the array is passed directly to the CodeIgniter database forge $forge->dropTable() method. An authenticated admin who tampers with the request body can substitute the original list with any table name present in the database.
The issue is a classic server-side trust failure where the client controls what should be a server-authoritative decision. CodeIgniter's dropTable() executes the requested DDL operation without further authorization context, so deletion succeeds against any reachable table.
Root Cause
The root cause is improper input validation [CWE-20] in deleteProcess(). The handler does not cross-check the submitted tables[] values against the file system list of tables owned by the targeted theme. This violates the principle that authorization decisions and resource scoping must be enforced server-side, not derived from client-supplied data.
Attack Vector
Exploitation requires authenticated access with administrative privileges to the CI4MS theme management interface. The attacker intercepts or crafts a POST request to the theme deletion endpoint and replaces the tables[] array with arbitrary table names such as users, sessions, or migrations. On submission, the affected handler iterates the supplied list and invokes $forge->dropTable() for each entry, dropping core application tables and corrupting the deployment.
No memory corruption, command injection, or authentication bypass is involved. The exploit consists solely of modifying form values in an otherwise legitimate administrative request. See the GitHub Security Advisory GHSA-vgrf-pr28-vf98 for the maintainer's analysis.
Detection Methods for CVE-2026-41890
Indicators of Compromise
- Unexpected DROP TABLE statements in the database server query log originating from the CI4MS application user.
- Application errors referencing missing core tables such as users, roles, or migrations immediately after a theme deletion request.
- POST requests to the CI4MS theme deleteProcess endpoint where tables[] values do not correspond to any installed theme's migration files.
Detection Strategies
- Audit web server access logs for POST requests targeting the theme deletion endpoint and correlate with the contents of submitted tables[] parameters.
- Compare submitted tables[] values against the on-disk migration files for each theme to identify tampered submissions.
- Enable database query logging on the application account and alert on any DROP TABLE statement issued outside scheduled migration windows.
Monitoring Recommendations
- Track the version string of CI4MS deployments and flag any instance still running between 0.31.1.0 and 0.31.7.x.
- Monitor administrative session activity for anomalous theme deletion attempts, especially from accounts that do not normally manage themes.
- Forward web and database logs to a centralized SIEM and create correlation rules linking theme deletion HTTP requests to subsequent schema changes.
How to Mitigate CVE-2026-41890
Immediate Actions Required
- Upgrade CI4MS to version 0.31.8.0 or later, which validates tables[] values against the theme's migration files server-side.
- Restrict administrative access to the CI4MS console using network controls and enforce strong authentication on all admin accounts.
- Take a verified database backup before deploying the patch so any prior tampering can be reversed.
Patch Information
The maintainers fixed the vulnerability in CI4MS 0.31.8.0. The patched deleteProcess() reconstructs the authoritative table list from the targeted theme's migration files and ignores client-supplied values that are not part of that list. Release notes are available in the CI4MS 0.31.8.0 release.
Workarounds
- Temporarily disable the theme deletion route in the CI4MS routing configuration until the upgrade is applied.
- Reduce the number of accounts with administrative privileges and require multi-factor authentication for those that remain.
- Apply database-level permissions that prevent the application user from issuing DROP TABLE statements against tables outside the theme namespace.
# Upgrade CI4MS to the patched release using Composer
composer require ci4-cms-erp/ci4ms:^0.31.8.0
php spark migrate
php spark cache:clear
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
