ByteCoreStack Plugin up to 1.2.3 on WordPress MCP Tool execute_tool uid privileges management

Summaryinfo

A vulnerability categorized as problematic has been discovered in ByteCoreStack Plugin up to 1.2.3. The impacted element is the function execute_tool of the component MCP Tool. The manipulation of the argument uid results in privileges management. This vulnerability was named CVE-2026-19807. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability, which was classified as problematic, was found in ByteCoreStack Plugin up to 1.2.3. Affected is the function execute_tool of the component MCP Tool. The manipulation of the argument uid with an unknown input leads to a privileges management vulnerability. CWE is classifying the issue as CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. This is going to have an impact on integrity. CVE summarizes:

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.

The advisory is available at wordfence.com. This vulnerability is traded as CVE-2026-19807 since 08/13/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/01/2026). This vulnerability is assigned to T1068 by the MITRE ATT&CK project.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• WordPress Plugin

Name

• ByteCoreStack Plugin

Version

• 1.2.0
• 1.2.1
• 1.2.2
• 1.2.3

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CPE 2.2info

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