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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-63223: 0.80% estimated exploitation activity in the next 30 days; percentile 56.62 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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 isimage or mimein without an independent safe extension check, such as extin on patched versions - save uploaded files using the client-supplied filename - place uploads in a web-accessible directory where PHP files can execute Patches Upgrade to v4.7.4 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 client filename. - Disable script execution in any public upload directory. - Manually verify the client filename extension before moving the file. - For image uploads, reject files when $file-getClientExtension() is not an allowed image extension. - For exact MIME-type validation, reject files when $file-getClientExtension() does not…

Published by the source

7 Aug 2026, 18:24 UTC

Last modified by the source

7 Aug 2026, 18:24 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-mmj4-63m4-r6h5

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# Patch Next advisory brief: CVE-2026-63223

Advisory: CodeIgniter: Uploaded file extension validation bypass in `is_image` and `mime_in` rules
IDs: CVE-2026-63223, GHSA-mmj4-63m4-r6h5
Record: https://patchnext.com/advisories/cve-2026-63223 (revision 1, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: codeigniter4/framework 4.7.4. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist codeigniter4/framework: affected < 4.7.4; fixed in 4.7.4

## Suggested inspection (read-only)
- Packagist codeigniter4/framework: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on codeigniter4/framework.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-mmj4-63m4-r6h5 (GitHub-reviewed advisory GHSA-mmj4-63m4-r6h5 lists affected ranges: Packagist codeigniter4/framework >=0 <4.7.4)

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