{"id":"CVE-2026-19807","revision":null,"records":[{"revision":"aa0d7b978bc64fb5853d888400acb79c","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-19807","aliases":[],"title":"ByteCoreStack <= 1.2.3 - Authenticated (Subscriber+) Privilege Escalation via wp_update_user_meta MCP Tool","description":"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.","state":0,"publishedAt":"2026-10-01T07:40:24.252+00:00","modifiedAt":"2026-10-03T15:42:52.096+00:00","affected":[{"ecosystem":"Vendor product","name":"ByteCoreStack – MCP Connector for AI Tools","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"bytecorestack\",\n                    \"product\": \"ByteCoreStack – MCP Connector for AI Tools\",\n                    \"versions\": [\n                        {\n                            \"version\": \"0\",\n                            \"status\": \"affected\",\n                            \"lessThanOrEqual\": \"1.2.3\",\n                            \"versionType\": \"semver\"\n                        }\n                    ],\n                    \"defaultStatus\": \"unaffected\"\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://www.wordfence.com/threat-intel/vulnerabilities/id/ac09bf3e-49cf-4f11-92ba-d1fbf6f587d7?source=cve","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2046","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2042","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2044","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L332","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/OAuth/Server.php#L122","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2046","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2042","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2044","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L332","https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/OAuth/Server.php#L122","https://plugins.trac.wordpress.org/changeset?reponame=&new=3711909%40bcs-mcp-manager%2Ftags%2F1.2.4&old=3711721%40bcs-mcp-manager%2Ftags%2F1.2.3","https://plugins.trac.wordpress.org/changeset/3711908/bcs-mcp-manager/trunk/includes/MCP/Server.php"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-19807","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-19807","identifiers":["CVE-2026-19807"]},"retained":false,"historicalAffected":[]}],"coverage":[{"source":"cisa-kev:global","scope":"Complete CISA KEV catalog; all vendors. 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