Arbitrary file upload in CodeIgniter4 - #VU155850
Published: October 15, 2026
Vulnerability identifier: #VU155850
CSH Severity: High
CVSS v4: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: N/A
CWE-ID: CWE-434
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to insufficient filename validation in the is_image and mime_in upload validation rules when processing filenames with trailing dots that conceal a PHP extension. A remote attacker can upload a file with a specially crafted filename to execute arbitrary code.
Exploitation requires the application to preserve client-supplied filenames in a web-accessible directory whose server configuration executes the uploaded files as PHP.
Affected software
CodeIgniter4
Remediation
Install security update from vendor's website.
CodeIgniter4 - update to 4.7.5