{"schema":"threatline.record/2","record":{"id":"CVE-2026-19807","aliases":[],"summary":"ByteCoreStack <= 1.2.3 - Authenticated (Subscriber+) Privilege Escalation via wp_update_user_meta MCP Tool","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.","categories":["Unclassified"],"product":"ByteCoreStack – MCP Connector for AI Tools","vendor":"bytecorestack","ecosystem":null,"affected_ranges":[{"source":"CVE List","source_url":"https://www.cve.org/CVERecord?id=CVE-2026-19807","source_modified_at":"2026-10-03T15:42:52.096Z","fetched_at":"2026-10-23T18:52:38.922436Z","product":"ByteCoreStack – MCP Connector for AI Tools","vendor":"bytecorestack","versions":[{"version":"0","status":"affected","lessThanOrEqual":"1.2.3","versionType":"semver"}],"defaultStatus":"unaffected"}],"fixed_versions":[],"cvss":8.8,"severity":"High","kev":{"listed":false},"epss":{"probability":0.00383,"percentile":0.31171,"score_date":"2026-10-23"},"published_at":"2026-10-01T07:40:24.252Z","modified_at":"2026-10-03T15:42:52.096Z","provenance":[{"source":"CVE List","url":"https://www.cve.org/CVERecord?id=CVE-2026-19807","fetched_at":"2026-10-23T18:52:38.922436Z","source_modified_at":"2026-10-03T15:42:52.096Z"},{"source":"EPSS","url":"https://api.first.org/data/v1/epss?cve=CVE-2026-19807","fetched_at":"2026-10-23T18:42:43.628194Z","source_modified_at":"2026-10-23"}],"sources":["CVE List","EPSS"],"references":[{"source":"CVE List","url":"https://www.wordfence.com/threat-intel/vulnerabilities/id/ac09bf3e-49cf-4f11-92ba-d1fbf6f587d7?source=cve"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2046"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2042"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L2044"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/MCP/Server.php#L332"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.2.0/includes/OAuth/Server.php#L122"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2046"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2042"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L2044"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/MCP/Server.php#L332"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/browser/bcs-mcp-manager/tags/1.1.0/includes/OAuth/Server.php#L122"},{"source":"CVE List","url":"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"},{"source":"CVE List","url":"https://plugins.trac.wordpress.org/changeset/3711908/bcs-mcp-manager/trunk/includes/MCP/Server.php"}],"locations":[],"motoko_assessment":{"status":"requires_architecture_review","automatic_remediation":false},"cve_state":"PUBLISHED","cvss_source":"CVE List","ssvc":{"exploitation":"none","automatable":"no","technical_impact":"total","assessed_at":"2026-10-03T15:35:38.770295Z"},"classification":{"method":"product-first software-layer rules","rules_version":"2.1","matched_on":null,"confidence":"unknown","reviewed":false},"change_timestamp":"2026-10-03T15:42:52.096Z","content_hash":"8f891bcfd5887dfd442b4272357e38a8a09e5ff1846aef474e592fa60ea4f21f"}}