CVE-2026-6401 svil4ok CVE debrief

Who should care

WordPress site administrators using the Bottom Bar plugin; security teams managing WordPress installations; developers maintaining WordPress plugins with administrative interfaces

Technical summary

The Bottom Bar plugin for WordPress versions 0.1.7 and earlier fails to implement Cross-Site Request Forgery protections on its administrative settings forms. The plugin's bottom-bar-admin.php file handles three settings forms (main settings, sharing services, restore defaults) without including wp_nonce_field() in the form markup and without calling check_admin_referer() or equivalent nonce validation functions when processing POST requests. This allows attackers to craft malicious requests that, when submitted by an authenticated administrator, modify plugin configuration options including language settings, maximum post counts, and enabled sharing services. The vulnerability requires user interaction (administrator action) and network access but no authentication for the attacker.

Defensive priority

medium

Recommended defensive actions

• Update Bottom Bar plugin to version 0.1.8 or later when available
• Apply WordPress core updates which may include hardened nonce handling
• Review plugin settings for unauthorized modifications if running affected versions
• Consider disabling or removing the plugin if updates are unavailable
• Implement Web Application Firewall rules to detect and block suspicious POST requests to wp-admin endpoints lacking proper nonce validation
• Enable WordPress security logging to monitor for unexpected option updates

Evidence notes

Vulnerability confirmed via source code analysis of bottom-bar-admin.php at lines 16 and 59 in both tagged release 0.1.7 and trunk. No wp_nonce_field() present in forms; no check_admin_referer() or equivalent server-side validation. Wordfence assigned CVE and published technical details.

Official resources