CVE-2026-49775: Welcart e-Commerce Auth Bypass Flaw

CVE-2026-49775 Overview

CVE-2026-49775 is a broken access control vulnerability affecting the Welcart e-Commerce plugin for WordPress, also known as usc-e-shop. The flaw exists in versions up to and including 2.11.28. The plugin fails to enforce authorization on one or more endpoints, allowing unauthenticated attackers to access functionality reserved for privileged users. The issue is tracked under CWE-862: Missing Authorization and is reported through Patchstack.

Critical Impact
Unauthenticated network attackers can interact with restricted plugin functionality, leading to limited integrity and availability impact across affected WordPress sites.

Affected Products

Welcart e-Commerce (usc-e-shop) WordPress plugin versions <= 2.11.28
WordPress installations running the vulnerable plugin
E-commerce sites built on the Welcart platform

Discovery Timeline

2026-06-15 - CVE-2026-49775 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2026-49775

Vulnerability Analysis

The vulnerability resides in the Welcart e-Commerce plugin (usc-e-shop) for WordPress. The plugin exposes one or more actions that lack capability checks or nonce validation. An unauthenticated attacker can issue HTTP requests to these endpoints and trigger functionality intended for authorized users. The attack vector is network-based and requires no user interaction.

The weakness maps to CWE-862 Missing Authorization. Plugins routinely register AJAX or REST handlers through hooks such as wp_ajax_nopriv_* or register_rest_route. When these handlers omit current_user_can() checks or skip nonce verification with check_ajax_referer(), any visitor can invoke them. The EPSS score for this issue is 0.191% at the time of publication.

Root Cause

The root cause is the absence of authorization checks on plugin actions that modify state or expose restricted data. The plugin trusts request parameters without verifying the caller's role or session context. This design omission converts privileged operations into unauthenticated entry points.

Attack Vector

Exploitation requires only network access to the WordPress site hosting the vulnerable plugin. An attacker crafts an HTTP request targeting the affected action handler and submits parameters that drive the unauthorized operation. No credentials, social engineering, or local access are required. The Patchstack advisory describes the affected endpoint and parameters.

No verified proof-of-concept code is currently published. Refer to the Patchstack Vulnerability Report for the technical write-up.

Detection Methods for CVE-2026-49775

Indicators of Compromise

Unauthenticated POST or GET requests to admin-ajax.php or Welcart REST routes from external IP addresses
Unexpected modifications to order, product, or customer records performed without an authenticated administrator session
Web server access logs showing repeated requests to usc-e-shop action handlers from a single source

Detection Strategies

Inventory WordPress installations and identify any running usc-e-shop at version 2.11.28 or earlier
Inspect request bodies hitting Welcart endpoints for parameter sets associated with privileged actions
Correlate web access logs with WordPress audit logs to identify state changes lacking a matching authenticated session

Monitoring Recommendations

Enable verbose logging in the WordPress reverse proxy or web application firewall (WAF) for /wp-admin/admin-ajax.php and /wp-json/ traffic
Alert on unauthenticated requests that invoke Welcart action names tied to administrative functions
Track plugin version inventory continuously to detect rollbacks to vulnerable releases

How to Mitigate CVE-2026-49775

Immediate Actions Required

Update the Welcart e-Commerce plugin to a version newer than 2.11.28 as soon as the vendor releases a fixed build
Restrict access to /wp-admin/admin-ajax.php and Welcart REST endpoints behind a WAF rule that blocks unauthenticated calls to privileged actions
Audit Welcart-managed data (orders, customers, products) for unauthorized modifications between the plugin install date and the patch date

Patch Information

Consult the Patchstack Vulnerability Report for the latest fixed version and vendor guidance. Patchstack mitigation rules may also be available for subscribers prior to vendor remediation.

Workarounds

Deploy a virtual patch through a WAF that denies unauthenticated requests to the affected Welcart action handlers
Temporarily disable the usc-e-shop plugin on sites that cannot apply the update immediately
Restrict administrative endpoints to known IP ranges using web server access controls until the patched version is installed

bash

# Example nginx rule to block unauthenticated access to Welcart AJAX actions
location = /wp-admin/admin-ajax.php {
    if ($arg_action ~* "^(usces_|welcart_)") {
        # Require an authenticated WordPress cookie
        if ($http_cookie !~* "wordpress_logged_in_") {
            return 403;
        }
    }
    include fastcgi_params;
    fastcgi_pass php_upstream;
}