Summary
CVE-2026-54847 is a high-severity Unauthenticated Broken Access Control vulnerability (CWE-862: Missing Authorization) affecting the Stylish Cost Calculator WordPress plugin in all versions up to and including 8.3.9. With a CVSS v3.1 base score of 7.5 (HIGH), the flaw can be exploited remotely by unauthenticated attackers with no user interaction required, resulting in unauthorized access to protected plugin functionality and significant confidentiality impact. Sites using this plugin for quote generation, lead capture, and cost estimation forms are at risk of exposing the business and customer data those forms collect.
Technical details
- Root cause: A missing authorization check within a plugin function fails to validate whether the requesting user has the required permissions before executing privileged operations. No nonce token verification is performed, allowing the access control boundary to be bypassed entirely.
- Trigger conditions: The vulnerability is exploitable by any unauthenticated network-adjacent or remote attacker. No credentials, session tokens, or prior site interaction are needed.
- Attack vector: Network-based (AV:N). The vulnerable function is reachable over standard HTTP/HTTPS without authentication (PR:N) and without any victim interaction (UI:N).
- Impact: Confidentiality impact is rated HIGH (C:H). Successful exploitation enables unauthorized actors to invoke privileged plugin operations. Given the plugin’s role in collecting quote submissions, lead generation data, customer contact details, and file uploads, this class of access control failure exposes sensitive business and personal information to unauthenticated parties. Integrity and availability are not directly impacted (I:N, A:N).
Affected software
- Stylish Cost Calculator (WordPress plugin, free edition) — all versions <= 8.3.9
- Stylish Cost Calculator Premium — versions <= 8.3.9
Severity
- CVSS v3.1 Base Score: 7.5 (HIGH)
- Vector string:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Mitigation and recommended actions
- Immediate action — update the plugin: Upgrade the Stylish Cost Calculator plugin to version 8.3.10 or later (current release: 8.4.3). The fix is available directly from the WordPress Plugin Repository and via the WordPress admin dashboard under Plugins → Updates.
- Audit lead/quote data access: Review WordPress access logs for unexpected or anonymous requests to plugin-related admin-ajax endpoints or plugin REST routes that predate the patch, as a precaution against prior unauthorized access.
- If immediate patching is not feasible: Restrict network access to the WordPress admin-ajax.php handler and any plugin-specific REST API routes at the web application firewall or reverse proxy layer to reduce exposure until the plugin can be updated.
IONIX Status
The IONIX research team is tracking ongoing exploitation attempts and recommends immediate patching. Potentially affected assets are outlined in this post.

