{
 "id": "WPSEC-2026-1299",
 "url": "https://wpsec.com/vuln/WPSEC-2026-1299/",
 "json_url": "https://wpsec.com/vuln/WPSEC-2026-1299/advisory.json",
 "markdown_url": "https://wpsec.com/vuln/WPSEC-2026-1299/index.md",
 "title": "Meta Box - WordPress Custom Fields Framework <= 5.15.2 - Authenticated (Contributor+) Stored Cross-Site Scripting via Background Field",
 "description": "The Meta Box plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the background field in all versions up to, and including, 5.15.2 due to the sanitizer preserving arbitrary submitted array keys and the formatter concatenating those keys into the output without escaping. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts that execute whenever a user accesses a page where the background field value is rendered. Exploitation requires a background field to be registered on content the attacker can edit.",
 "plugin": {
  "slug": "meta-box",
  "name": "Meta Box - WordPress Custom Fields Framework",
  "full_name": "Meta Box – A Framework for Dynamic Websites",
  "wordpress_org": "https://wordpress.org/plugins/meta-box/",
  "advisories_url": "https://wpsec.com/vuln/plugin/meta-box/",
  "attacksurface": "https://attacksurface.wpsec.com/plugin/meta-box"
 },
 "type": "XSS",
 "cwe": [
  "CWE-79"
 ],
 "cve": [],
 "cvss": {
  "version": "3.1",
  "score": 6.4,
  "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N",
  "severity": "Medium"
 },
 "affected": {
  "ranges": [
   {
    "from": null,
    "from_inclusive": true,
    "to": "5.15.3",
    "to_inclusive": false
   }
  ],
  "text": [
   "all versions before 5.15.3"
  ]
 },
 "introduced_in": null,
 "fixed_in": "5.15.3",
 "remediation": "Update to 5.15.3 or later.",
 "fix_released": "2026-10-20T02:20:02+00:00",
 "published": "2026-10-21T10:43:36+00:00",
 "updated": "2026-10-21T10:35:14.131920+00:00",
 "also_published_as": null,
 "references": [
  "https://wpsec.com/vuln/WPSEC-2026-1299/",
  "https://plugins.svn.wordpress.org/meta-box/tags/5.15.3/",
  "https://wordpress.org/plugins/meta-box/"
 ],
 "attacksurface_url": "https://attacksurface.wpsec.com/plugin/meta-box",
 "source": "WPSec",
 "license": {
  "name": "CC BY 4.0",
  "url": "https://creativecommons.org/licenses/by/4.0/"
 },
 "usage": {
  "plugin": "Low",
  "affected_versions": "Low",
  "as_of": "2026-10-21"
 }
}