Vulnerability · Published Jul 17, 2026 · Assigned by GitHub_M
CVE-2026-48062CodeIgniter: Uploaded file extension validation bypass in `ext_in` rule
Critical 9.8
In plain English
A critical-severity unrestricted file upload in CodeIgniter4 from codeigniter4. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.8% (higher than 56% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
CodeIgniter is a PHP full-stack web framework. Prior to 4.7.3, the ext_in upload validation rule in system/Validation/StrictRules/FileRules.php checked the MIME-derived guessed extension instead of the client-provided filename extension. As a result, an uploaded file named shell.php containing GIF-like content could pass validation such as uploaded[avatar]|is_image[avatar]|mime_in[avatar,image/gif]|ext_in[avatar,gif] because the detected MIME type maps to gif, even though the uploaded filename extension is php. Applications are impacted if they accept user-controlled uploads, rely on ext_in to validate the uploaded filename extension, save uploaded files using the original client filename with $file->move($path), store uploads in a web-accessible directory, and allow PHP or other executable files to run from that directory. In those conditions, this may lead to arbitrary code execution. This issue is fixed in version 4.7.3.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Packagist | codeigniter4/framework | 4.7.3 | GHSA-2gr4-ppc7-7mhx |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| codeigniter4 | CodeIgniter4 | < 4.7.3 |
Weakness: CWE-434 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H