CVE-2026-111958: Royal MCP authentication bypass vulnerability
high 7.5 published 2026-10-22
- Affected versions
- older than 1.5.7
- Fixed in
- 1.5.7
- Latest version
- 1.5.14
- Severity
- High · CVSS 7.5
- Active installs
- 10,000+
- Type
- Authentication bypass
What an attacker needs
- Access: A low-level account on the site, such as a subscriber or customer (per the CVSS score).
CVSS vector (score by CISA ADP): CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
What to do now
- Update Royal MCP to 1.5.7 or newer (the latest is 1.5.14): Dashboard → Updates, or Plugins → “update now”.
- If you cannot update right away, deactivate it until you can.
- Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
- Not sure which version you run? Check your version against every known Royal MCP issue.
With WP-CLI:
wp plugin get royal-mcp --field=version. - If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.
The advisory
The Royal MCP WordPress plugin before 1.5.7 does not limit a preview-link token to the single preview it was issued for, so any party that obtains a valid token is authenticated as the token's owning user, an administrator in the default configuration, across the entire REST API with no nonce, leading to full site takeover.
References
- NVD CVE-2026-111958 nvd.nist.gov
- WPScan advisory wpscan.com
Related
Ran an affected version? Check your site for signs of a hack
The free scan reads the public side of your site and looks for spam pages, hidden redirects, injected scripts and blacklist entries. No login, no install, about a minute.
Where this data comes from
- CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
- Versions and install counts: wordpress.org/plugins/royal-mcp (Plugins API), fetched 2026-11-04.
- The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.