CVE-2026-48062
CodeIgniter4 has a validation bypass when uploading file extensions via `ext_in` rule
描述
### 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](https://cwe.mitre.org/data/definitions/434.html) - [OWASP File Upload Cheat Sheet](https://cheatsheetseries.owasp.org/cheatsheets/File_Upload_Cheat_Sheet.html)
如何修補 CVE-2026-48062
要修補 CVE-2026-48062,請將受影響套件升級到下列已修補版本。
- —升級至 4.7.3 或更新版本
CVE-2026-48062 正在被利用嗎?
目前沒有被利用訊號。CVE-2026-48062 既不在 CISA KEV 也沒有最新的 EPSS 分數。