CVE-2026-48062 CodeIgniter: Uploaded file extension validation bypass in `ext_in` rule
Attackers can upload malicious PHP files disguised as images to achieve arbitrary code execution if the application uses specific upload validation rules and stores files in web-accessible directories.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-48062?
CVE-2026-48062 is a critical vulnerability in CodeIgniter4, published on 17 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
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.
Weakness: CWE-434
Which versions are affected by CVE-2026-48062?
2 open source packages ship an affected version, including codeigniter4/framework.
| Package | Affected | Fixed in |
|---|---|---|
codeigniter4/framework Packagist | All versions | 4.7.3 |
codeigniter4/framework Packagist | All versions | 4.7.3 |
How do I fix CVE-2026-48062?
Upgrade codeigniter4/framework to 4.7.3 or later.
Is CVE-2026-48062 being exploited?
There is no known exploitation of CVE-2026-48062 in the wild and no public exploit code.
Sources
Also known as GHSA-2gr4-ppc7-7mhx.