[GHSA] GHSA-mmj4-63m4-r6h5 (critical) — CodeIgniter: Uploaded file extension validation bypass in `is_image` and `mime_in` rules

GHSA-mmj4-63m4-r6h5 Severity: critical CVE: CVE-2026-63223

CodeIgniter: Uploaded file extension validation bypass in `is_image` and `mime_in` rules

### Impact This is an unsafe file upload validation vulnerability that can lead to remote code execution in vulnerable application configurations.

Applications are impacted when they: - validate uploads using `is_image` or `mime_in` without an indep