GHSA-CW7V-45WM-MCF2

Vulnerability from github – Published: 2026-03-27 22:21 – Updated: 2026-03-27 22:21
VLAI?
Summary
Kirby CMS has Persistent DoS via Malformed Image Upload
Details

Summary

Kirby CMS through version 5.1.4 allows an authenticated user with Editor permissions to cause a persistent Denial of Service (DoS) via a malformed image upload.

Details

The vulnerability is caused by improper validation of the return value of PHP's getimagesize() function. When a malformed file is uploaded with a valid image extension (e.g., .jpg), the function returns false instead of an expected array.

The application fails to handle this condition properly and proceeds with image processing, resulting in a fatal TypeError. This leads to persistent application crashes when the affected file is accessed.

Impact

  • Persistent Denial of Service (DoS)
  • Affected pages return HTTP 500 errors
  • Requires manual removal of the malformed file to restore functionality
  • Exploitable by authenticated users with Editor permissions
Severity ?
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Show details on source website
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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "getkirby/cms"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.2.0-rc.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-29905"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-27T22:21:26Z",
    "nvd_published_at": "2026-03-26T17:16:34Z",
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nKirby CMS through version 5.1.4 allows an authenticated user with Editor permissions to cause a persistent Denial of Service (DoS) via a malformed image upload.\n\n## Details\n\nThe vulnerability is caused by improper validation of the return value of PHP\u0027s `getimagesize()` function. When a malformed file is uploaded with a valid image extension (e.g., `.jpg`), the function returns `false` instead of an expected array.\n\nThe application fails to handle this condition properly and proceeds with image processing, resulting in a fatal `TypeError`. This leads to persistent application crashes when the affected file is accessed.\n\n## Impact\n\n- Persistent Denial of Service (DoS)\n- Affected pages return HTTP 500 errors\n- Requires manual removal of the malformed file to restore functionality\n- Exploitable by authenticated users with Editor permissions",
  "id": "GHSA-cw7v-45wm-mcf2",
  "modified": "2026-03-27T22:21:26Z",
  "published": "2026-03-27T22:21:26Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/Stalin-143/CVE-2026-29905/security/advisories/GHSA-cw7v-45wm-mcf2"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-29905"
    },
    {
      "type": "WEB",
      "url": "https://drive.google.com/file/d/1MwvvSYIwnC8kOIzjycGMQZw4d2K2ef8h/view?usp=sharing"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Stalin-143/CVE-2026-29905"
    },
    {
      "type": "WEB",
      "url": "https://github.com/getkirby/kirby/releases/tag/5.2.0-rc.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Kirby CMS has Persistent DoS via Malformed Image Upload"
}


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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
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  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



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