ByteCoreStack MCP Connector for AI Tools: Privilege escalation for subscribers
Summary
The WordPress plugin ByteCoreStack MCP Connector for AI Tools up to and including version 1.2.2 contains a privilege escalation flaw (CWE-266). An attacker with a valid Subscriber account can gain administrator rights and take full control of the WordPress site. The plugin's MCP endpoints are reachable without a WordPress login by design, so the attack surface is public. No evidence of active exploitation has been found so far.
Affected
- ByteCoreStack MCP Connector for AI Tools (WordPress plugin, slug bcs-mcp-manager) up to and including 1.2.2
- Related CVE-2026-19807 reports a further privilege escalation in versions up to and including 1.2.3, so later versions should be verified as well
Fixed in
- Version 1.2.4 or later according to Patchstack and the CVE record
- No vendor advisory was found to confirm this
Workaround
- No vendor workaround known.
- If the update cannot be applied immediately, deactivate the plugin or at least its MCP connector.
- Restrict or disable open user registration if it is not needed.
Exploitation
- No evidence of active exploitation found.
- CISA SSVC: exploitation none, not automatable, total technical impact.
- Patchstack rates the issue as high priority and expects exploitation.
Our recommendation
- Check whether the plugin is installed and which version is active.
- Update to version 1.2.4 or later immediately.
- If an update is not possible, deactivate the plugin.
- Audit subscriber and other low-privilege accounts for unexpected administrator roles.
- Review logs for MCP/OAuth endpoint requests from unknown clients.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- Patchstack advisory for CVE-2026-103068 patchstack.com
- Strix CVE page for CVE-2026-103068 www.strix.ai
- GitHub issue mirroring the NVD record for CVE-2026-103068 github.com
- WordPress.org plugin page for bcs-mcp-manager en-ca.wordpress.org
- VulDB entry for related CVE-2026-19807 vuldb.com
- Strix CVE page for related CVE-2026-19807 www.strix.ai
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 31 Oct 2026, 22:58.
Original description (NVD)
Subscriber Privilege Escalation in ByteCoreStack – MCP Connector for AI Tools <= 1.2.2 versions.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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