PT-2026-48810 · Packagist · Codeigniter4/Framework

Published 2026-06-11 · Updated 2026-06-11 · CVE-2026-48062

OSV

CVSS v3.1

9.8

Critical

Base vector

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

Impact

The ext in upload validation rule 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: $file->move($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. The default application does not expose such an upload endpoint.

Patches

Upgrade to v4.7.3 or later.

Workarounds

• Save uploads outside the public web root, preferably under writable/uploads
• Use $file->store() or $file->move($path, $file->getRandomName()) instead of preserving the original filename
• Disable script execution in any public upload directory
• Manually verify the client filename extension before moving the file
• Reject files when $file->getClientExtension() is not in the allowed list or does not match $file->guessExtension()

Resources

• [CodeIgniter4 uploaded files documentation](https://codeigniter.com/user guide/libraries/uploaded files.html#moving-files)
• [CodeIgniter4 file upload validation documentation](https://codeigniter.com/user guide/libraries/validation.html#rules-for-file-uploads)
• CWE-434: Unrestricted Upload of File with Dangerous Type
• [OWASP File Upload Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/File Upload Cheat Sheet.html)

Fix

Unrestricted File Upload

Weakness Enumeration

CWE-434

Related Identifiers

CVE-2026-48062

GHSA-2GR4-PPC7-7MHX

Affected Products

Codeigniter4/Framework

References · 7

• https://osv.dev/vulnerability/GHSA-2gr4-ppc7-7mhx · Vendor Advisory
• https://github.com/codeigniter4/CodeIgniter4 · Note
• https://github.com/codeigniter4/CodeIgniter4/commit/29299349e7d232e9532767c7cefaed30957309be · Note
• https://github.com/codeigniter4/CodeIgniter4/blob/develop/CHANGELOG.md · Note
• https://github.com/codeigniter4/CodeIgniter4/security/advisories/GHSA-2gr4-ppc7-7mhx · Note
• https://codeigniter.com/user_guide/libraries/uploaded_files.html#moving-files · Note
• https://codeigniter.com/user_guide/libraries/validation.html#rules-for-file-uploads · Note