CVE-2026-39393 HIGH

CVE-2026-39393: Post-Installation Re-entry via Cache-Dependent Install Guard Bypass in ci4ms

Vendor Ci4-Cms-Erp
Product ci4ms
Weakness CWE-306 · Missing auth
Published April 8, 2026
Last update April 10, 2026

CVSS base score

8.1/10
Attack vector Network
Attack complexity High
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to 0.31.4.0, the install route guard in ci4ms relies solely on a volatile cache check (cache('settings')) combined with .env file existence to block post-installation access to the setup wizard. When the database is temporarily unreachable during a cache miss (TTL expiry or admin-triggered cache clear), the guard fails open, allowing an unauthenticated attacker to overwrite the .env file with attacker-controlled database credentials, achieving full application takeover. This vulnerability is fixed in 0.31.4.0.

Key dates

02Disclosure timeline

April 8, 2026 CVE published
April 10, 2026 Record updated