GHSA-QWVR-5FHH-47XH

Vulnerability from github – Published: 2026-10-01 09:30 – Updated: 2026-10-01 09:30
VLAI
Details

The ByteCoreStack – MCP Connector for AI Tools plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.2.3 This is due to the wp_update_user_meta MCP tool in execute_tool gating writes solely with current_user_can('edit_user', $uid) — a check that WordPress core's map_meta_cap resolves to the read primitive when the target user ID matches the caller's own — while enforcing an incomplete meta key blocklist that covers only user_pass, user_activation_key, and session_tokens, leaving the wp_capabilities and wp_user_level meta keys entirely unprotected. This makes it possible for authenticated attackers with Subscriber-level access and above to elevate their privileges to Administrator by issuing a wp_update_user_meta call over the MCP JSON-RPC endpoint with key=wp_capabilities and an arbitrary role array such as {'administrator': true} targeting their own user ID, causing WordPress to load that account as an Administrator on the next request.

Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-19807"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-269"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-01T08:16:51Z",
    "severity": "HIGH"
  },
  "details": "The ByteCoreStack \u2013 MCP Connector for AI Tools plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.2.3 This is due to the `wp_update_user_meta` MCP tool in `execute_tool` gating writes solely with `current_user_can(\u0027edit_user\u0027, $uid)` \u2014 a check that WordPress core\u0027s `map_meta_cap` resolves to the `read` primitive when the target user ID matches the caller\u0027s own \u2014 while enforcing an incomplete meta key blocklist that covers only `user_pass`, `user_activation_key`, and `session_tokens`, leaving the `wp_capabilities` and `wp_user_level` meta keys entirely unprotected. This makes it possible for authenticated attackers with Subscriber-level access and above to elevate their privileges to Administrator by issuing a `wp_update_user_meta` call over the MCP JSON-RPC endpoint with `key=wp_capabilities` and an arbitrary role array such as `{\u0027administrator\u0027: true}` targeting their own user ID, causing WordPress to load that account as an Administrator on the next request.",
  "id": "GHSA-qwvr-5fhh-47xh",
  "modified": "2026-10-01T09:30:33Z",
  "published": "2026-10-01T09:30:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-19807"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2042"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2044"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2046"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L332"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/OAuth/Server.php#L122"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2042"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2044"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2046"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L332"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/OAuth/Server.php#L122"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset/3711908/bcs-mcp-manager/trunk/includes/MCP/Server.php"
    },
    {
      "type": "WEB",
      "url": "https://plugins.trac.wordpress.org/changeset?reponame=\u0026new=3711909%40bcs-mcp-manager%2Ftags%2F1.2.4\u0026old=3711721%40bcs-mcp-manager%2Ftags%2F1.2.3"
    },
    {
      "type": "WEB",
      "url": "https://www.wordfence.com/threat-intel/vulnerabilities/id/ac09bf3e-49cf-4f11-92ba-d1fbf6f587d7?source=cve"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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