CVE-2026-28153 Overview
CVE-2026-28153 is an unauthenticated broken access control vulnerability in the Notification Master WordPress plugin, which provides real-time notifications through email, SMS, and webhooks. The flaw affects versions up to and including 1.7.1. Attackers can reach protected functionality over the network without authentication or user interaction. The weakness is classified as Missing Authorization [CWE-862]. Successful exploitation allows unauthorized access to plugin resources, exposing confidential data managed by the plugin. The vulnerability affects any WordPress site running a vulnerable version of the plugin, regardless of user role configuration.
Critical Impact
Remote unauthenticated attackers can access restricted plugin functionality, resulting in confidentiality loss on affected WordPress installations.
Affected Products
- Notification Master – Real-Time WordPress Notifications With Email, SMS, Webhooks & More plugin
- All plugin versions <= 1.7.1
- WordPress installations with the plugin activated
Discovery Timeline
- 2026-08-24 - CVE-2026-28153 published to NVD
- 2026-08-24 - Last updated in NVD database
Technical Details for CVE-2026-28153
Vulnerability Analysis
The Notification Master plugin exposes functionality that lacks proper authorization checks. An unauthenticated attacker can invoke plugin endpoints or actions that should be restricted to privileged users. Because the attack traverses the network and requires no credentials or user interaction, exploitation is straightforward against any reachable WordPress site running a vulnerable version. The impact centers on confidentiality: attackers can retrieve information handled by the plugin, including notification content, configured recipients, or channel configuration such as webhooks and SMS integrations.
Root Cause
The root cause is a Missing Authorization weakness [CWE-862]. The plugin registers actions or handlers without verifying the caller's capability or nonce before executing sensitive operations. WordPress plugins typically enforce access control through current_user_can() capability checks and check_ajax_referer() nonce validation. When these checks are absent from AJAX or REST endpoints, any unauthenticated visitor can invoke the underlying logic directly.
Attack Vector
Exploitation occurs over the network against the WordPress site's HTTP interface. An attacker crafts a request to the vulnerable plugin endpoint, typically through admin-ajax.php or a REST route registered by the plugin. No authentication cookies, API keys, or user interaction are required. Refer to the PatchStack Vulnerability Report for endpoint-level technical details.
Detection Methods for CVE-2026-28153
Indicators of Compromise
- Unauthenticated HTTP requests to admin-ajax.php with action parameters referencing Notification Master handlers
- Requests to plugin REST routes under /wp-json/ targeting Notification Master namespaces from unfamiliar source addresses
- Unexpected access-log entries from residential proxies or scanner user agents hitting plugin endpoints
Detection Strategies
- Inventory WordPress installations and enumerate installed plugin versions to identify Notification Master <= 1.7.1
- Deploy web application firewall rules that flag anonymous requests to plugin-specific AJAX and REST endpoints
- Correlate HTTP access logs with notification configuration changes or webhook outbound traffic
Monitoring Recommendations
- Forward WordPress access logs and PHP error logs to a central analytics platform for anomaly review
- Track high request rates against admin-ajax.php and /wp-json/ routes from single source addresses
- Monitor outbound connections from the web host to webhook destinations that were not administratively configured
How to Mitigate CVE-2026-28153
Immediate Actions Required
- Update the Notification Master plugin to a version released after 1.7.1 that includes the authorization fix
- If no fixed version is available, deactivate and remove the plugin until a patch is confirmed
- Review notification configurations, recipients, and webhook targets for unauthorized modifications
- Rotate any credentials or API tokens stored within the plugin configuration
Patch Information
Consult the PatchStack Vulnerability Report for vendor patch status. Apply plugin updates through the WordPress admin dashboard or by replacing plugin files from the official repository once a fixed release is available.
Workarounds
- Restrict access to wp-admin/admin-ajax.php and /wp-json/ routes with web application firewall rules requiring authenticated sessions where feasible
- Apply IP allowlisting to WordPress administrative and REST endpoints on sites with a bounded user base
- Disable the Notification Master plugin until an updated version is installed
# Configuration example: identify vulnerable installations via WP-CLI
wp plugin list --field=name,version | grep notification-master
wp plugin deactivate notification-master
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
