Arbitrary file upload in Codeigniter4
CVE-2026-63223
CodeIgniter is a PHP full-stack web framework. Prior to 4.7.4, the is_image and mime_in upload validation rules do not independently enforce a safe client filename extension, allowing a remote attacker to upload executable content when an application preserves the client filename and stores uploads in a web-accessible script-enabled directory. Applications are impacted when they validate uploads using is_image or mime_in without an independent safe extension check (such as ext_in on patched versions), save uploaded files using the client-supplied filename, and place uploads in a web-accessible directory where PHP files can execute. This issue is fixed in version 4.7.4.
Vulnerability class: Unrestricted File Upload
EPSS: 0.008 (53.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
Affected products
- Codeigniter4 — versions < 4.7.4
Weakness classification (CWE)
Public proof-of-concept exploits
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-63223?
- CVE-2026-63223 is a critical-severity vulnerability in Codeigniter4, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2026-07-31.
- How severe is CVE-2026-63223?
- Critical severity. CVSS v3 base score is 9.8 out of 10.
- Is CVE-2026-63223 known to be exploited?
- 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.