CVE-2026-27409: Webba Booking Auth Bypass Vulnerability

CVE-2026-27409 Overview

CVE-2026-27409 is a Missing Authorization vulnerability [CWE-862] in the Webba Booking plugin for WordPress developed by Webba Plugins. The flaw stems from incorrectly configured access control security levels within plugin functionality. The vulnerability affects Webba Booking versions from an unspecified initial release through 6.4.13. Unauthenticated attackers can reach protected functionality over the network without user interaction. The issue impacts integrity to a limited degree, while confidentiality and availability remain unaffected.

Critical Impact
Unauthenticated remote attackers can bypass access controls in Webba Booking through version 6.4.13 to interact with functionality that should require authorization, resulting in limited integrity impact on affected WordPress sites.

Affected Products

Webba Plugins Webba Booking (WordPress plugin)
Versions from n/a through 6.4.13
WordPress sites running the vulnerable plugin

Discovery Timeline

2026-07-01 - CVE-2026-27409 published to the National Vulnerability Database (NVD)
2026-07-01 - Last updated in NVD database

Technical Details for CVE-2026-27409

Vulnerability Analysis

CVE-2026-27409 is classified as a Broken Access Control weakness [CWE-862 Missing Authorization]. The Webba Booking plugin exposes functionality without verifying whether the requesting user has the required permissions. Because the plugin operates within WordPress and is reachable over HTTP(S), any remote actor can send requests to the vulnerable endpoints. The Patchstack advisory categorizes the issue as broken access control resulting from incorrectly configured access control security levels. The impact is limited to integrity, meaning attackers can modify or influence data handled by the plugin without gaining read access to confidential information or disrupting availability.

Root Cause

The root cause is missing authorization checks on plugin endpoints. Booking-related actions do not consistently verify user capabilities or nonce validity before executing privileged operations. This allows requests to reach handlers that should be restricted to authenticated administrators or authorized roles. The condition falls under CWE-862, where a product does not perform an authorization check when an actor attempts to access a resource or perform an action.

Attack Vector

The attack vector is Network with low attack complexity and no privileges or user interaction required. An attacker crafts HTTP requests to affected Webba Booking endpoints on a target WordPress site. Because authorization is not enforced, the request executes with the effective permissions of the exposed handler. The Exploit Prediction Scoring System (EPSS) probability is 0.2%, and no public exploit or CISA KEV listing is currently associated with this CVE. Refer to the Patchstack Vulnerability Report for technical specifics.

No verified public exploit code is available for this vulnerability. Consult the vendor advisory for technical details on the vulnerable code paths.

Detection Methods for CVE-2026-27409

Indicators of Compromise

Unexpected changes to booking records, availability calendars, or plugin configuration in Webba Booking
HTTP requests to Webba Booking admin-ajax.php actions or REST endpoints from unauthenticated sessions
New or modified booking entries originating from unusual IP addresses or user agents

Detection Strategies

Review WordPress access logs for POST requests targeting Webba Booking endpoints without valid authentication cookies
Correlate plugin data modifications with the absence of an authenticated administrator session at the time of the change
Deploy web application firewall (WAF) rules that flag anonymous access to plugin actions requiring authorization

Monitoring Recommendations

Enable WordPress audit logging to record plugin state changes and administrative actions
Monitor the installed version of Webba Booking and alert when versions at or below 6.4.13 are detected
Track outbound notifications and confirmation emails triggered by booking actions to identify anomalous activity

How to Mitigate CVE-2026-27409

Immediate Actions Required

Identify all WordPress sites running Webba Booking version 6.4.13 or earlier
Update Webba Booking to a version released after 6.4.13 that resolves the missing authorization issue
Restrict access to /wp-admin/admin-ajax.php and plugin REST routes with a WAF where feasible
Audit booking data and plugin configuration for unauthorized modifications

Patch Information

Refer to the Patchstack Vulnerability Report for remediation guidance. The advisory indicates the vulnerability affects Webba Booking through version 6.4.13. Apply the fixed release provided by Webba Plugins as soon as it is available through the WordPress plugin repository.

Workarounds

Deactivate the Webba Booking plugin until a patched version is installed if immediate updating is not possible
Block anonymous access to Webba Booking endpoints at the reverse proxy or WAF layer
Restrict administrative and plugin endpoints to trusted IP ranges where operationally feasible

bash

# Configuration example: block unauthenticated access to Webba Booking AJAX actions via nginx
location = /wp-admin/admin-ajax.php {
    if ($arg_action ~* "^webba_") {
        # Require an authenticated WordPress session cookie
        if ($http_cookie !~* "wordpress_logged_in_") {
            return 403;
        }
    }
    include fastcgi_params;
    fastcgi_pass php_upstream;
}