GHSA-MMJ4-63M4-R6H5

Vulnerability from github – Published: 2026-08-07 18:24 – Updated: 2026-08-07 18:24
VLAI
Summary
CodeIgniter: Uploaded file extension validation bypass in `is_image` and `mime_in` rules
Details

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 independent safe extension check, such as ext_in 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 match $file->guessExtension().
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "codeigniter4/framework"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "4.7.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-63223"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-434"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-08-07T18:24:21Z",
    "nvd_published_at": "2026-07-31T06:16:32Z",
    "severity": "CRITICAL"
  },
  "details": "### Impact\nThis is an unsafe file upload validation vulnerability that can lead to remote code execution in vulnerable application configurations.\n\nApplications are impacted when they:\n- validate uploads using `is_image` or `mime_in` without an independent safe extension check, such as `ext_in` on patched versions\n- save uploaded files using the client-supplied filename\n- place uploads in a web-accessible directory where PHP files can execute\n\n### Patches\nUpgrade to v4.7.4 or later.\n\n### Workarounds\n- Save uploads outside the public web root, preferably under `writable/uploads`.\n- Use `$file-\u003estore()` or `$file-\u003emove($path, $file-\u003egetRandomName())` instead of preserving the original client filename.\n- Disable script execution in any public upload directory.\n- Manually verify the client filename extension before moving the file.\n- For image uploads, reject files when `$file-\u003egetClientExtension()` is not an allowed image extension.\n- For exact MIME-type validation, reject files when `$file-\u003egetClientExtension()` does not match `$file-\u003eguessExtension()`.",
  "id": "GHSA-mmj4-63m4-r6h5",
  "modified": "2026-08-07T18:24:21Z",
  "published": "2026-08-07T18:24:21Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/codeigniter4/CodeIgniter4/security/advisories/GHSA-mmj4-63m4-r6h5"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63223"
    },
    {
      "type": "WEB",
      "url": "https://github.com/codeigniter4/CodeIgniter4/commit/b6e9a4fa1dca2df3d3f261bdf61532df8c6420aa"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/codeigniter4/CodeIgniter4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/codeigniter4/CodeIgniter4/releases/tag/v4.7.4"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "CodeIgniter: Uploaded file extension validation bypass in `is_image` and `mime_in` rules"
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
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  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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