CVE-2026-63000: REDAXO Remote Code Execution Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-m8r3-22v6-g877",
  "modified" : "2026-09-23T14:09:15Z",
  "published" : "2026-09-23T14:09:15Z",
  "aliases" : [ "CVE-2026-63000" ],
  "summary" : "REDAXO: Missing CSRF Protection on Package Update Action Allows Forced Addon Updates",
  "details" : "### Summary\nThe `rex_api_install_package_update` API function (`install` addon) does not override `requiresCsrfProtection()`, which defaults to `false` in the base class `rex_api_function`. Any authenticated admin can therefore be tricked via a CSRF attack into silently triggering a package update from the REDAXO package server.\n\n### Details\n**File:** `redaxo/src/core/lib/api_function.php:277-280`\n```php\nprotected function requiresCsrfProtection()\n{\n    return false;  // DEFAULT — subclasses must opt in\n}\n```\n\n**File:** `redaxo/src/addons/install/lib/api/api_package_update.php:8-39`\n```php\nclass rex_api_install_package_update extends rex_api_function\n{\n    public function execute()\n    {\n        if (!rex::getUser()?->isAdmin()) {\n            throw new rex_api_exception('You do not have the permission!');\n        }\n        $addonkey = rex_request('addonkey', 'string');\n        $fileId = rex_request('file', 'int');\n        $installer = new rex_install_package_update();\n        // ... downloads and installs $addonkey version $fileId from redaxo.org\n    }\n    // requiresCsrfProtection() NOT overridden — defaults to false\n}\n```\n\nFor comparison, `rex_api_install_package_add` and `rex_api_install_package_delete` both correctly return `true`. Only `rex_api_install_package_update` is missing this.\n\n### PoC\n```html\n<!-- Attacker-controlled page -->\n<img src=\"https://victim-redaxo.example.com/index.php?page=install/packages&rex-api-call=install_package_update&addonkey=some_addon&file=42\" />\n```\nWhen an authenticated admin visits this page, the request is automatically made with their session cookie, causing `some_addon` to be updated to version `file_id=42`.\n\n### Impact\nAn attacker who can lure an admin to a malicious page can force-install specific addon versions. If combined with a supply-chain compromise of a package on redaxo.org, or by targeting a downgrade to a known-vulnerable version, this becomes a remote code execution vector. Even without supply-chain compromise, it can be used to disrupt the site by forcing unwanted updates.\n\n### Fix\nAdd `requiresCsrfProtection()` to `rex_api_install_package_update`:\n```php\nprotected function requiresCsrfProtection()\n{\n    return true;\n}\n```",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:H/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "redaxo/source"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.21.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.21.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/redaxo/core/security/advisories/GHSA-m8r3-22v6-g877"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/redaxo/core/pull/6579"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/redaxo/core/commit/a13abbffbad4fdea46a4edc86cdba3335ca9e8f3"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/redaxo/core"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/redaxo/core/releases/tag/5.21.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-352" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-23T14:09:15Z",
    "nvd_published_at" : null
  }
}