What’s Vulnerable › Vulnerabilities

CVE-2026-63223: CodeIgniter: Uploaded file extension validation bypass in is_image and mime_in rules

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.8% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-31 · updated 2026-09-08
• Weakness: CWE-434

Description

CodeIgniter is a PHP full-stack web framework. Prior to 4.7.4, the is_image and mime_in upload validation rules do not independently enforce a safe client filename extension, allowing a remote attacker to upload executable content when an application preserves the client filename and stores uploads in a web-accessible script-enabled directory. Applications are impacted when they validate uploads using is_image or mime_in without an independent safe extension check (such as ext_in on patched versions), save uploaded files using the client-supplied filename, and place uploads in a web-accessible directory where PHP files can execute. This issue is fixed in version 4.7.4.

Affected products

• CodeIgniter4: before 4.7.4

References

• https://github.com/codeigniter4/CodeIgniter4/commit/b6e9a4fa1dca2df3d3f261bdf61532df8c6420aa
• https://github.com/codeigniter4/CodeIgniter4/releases/tag/v4.7.4
• https://github.com/codeigniter4/CodeIgniter4/security/advisories/GHSA-mmj4-63m4-r6h5

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