CVE-2025-48327: WP Mailgun SMTP Auth Bypass Vulnerability

CVE-2025-48327 Overview

CVE-2025-48327 is a Missing Authorization vulnerability [CWE-862] affecting the inkthemes WP Mailgun SMTP plugin for WordPress. The flaw affects all versions from n/a through 1.0.7. Attackers can access plugin functionality that is not properly constrained by Access Control Lists (ACLs). The vulnerability is exploitable over the network without authentication or user interaction.

Critical Impact
Unauthenticated attackers can reach protected plugin functionality on affected WordPress installations, resulting in a limited confidentiality impact on WP Mailgun SMTP configuration data.

Affected Products

inkthemes WP Mailgun SMTP plugin for WordPress
All versions up to and including 1.0.7
WordPress sites with the wp-mailgun-smtp plugin installed and active

Discovery Timeline

2025-08-28 - CVE-2025-48327 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-48327

Vulnerability Analysis

The WP Mailgun SMTP plugin exposes functionality that fails to verify the caller's authorization before executing. The plugin registers endpoints or actions that check whether a user is authenticated but do not validate whether the user holds the required capability or role. Attackers reach these endpoints directly over HTTP without credentials.

The vulnerability aligns with CWE-862, Missing Authorization. Affected functionality relates to SMTP configuration handled by the plugin, which stores mail delivery settings including the Mailgun API context. Successful exploitation returns information that should be restricted to WordPress administrators.

The EPSS probability is 0.27%, placing the vulnerability in the 18.77th percentile for exploitation likelihood. No public proof-of-concept exploit is currently available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog.

Root Cause

The root cause is the absence of a capability check on plugin actions. WordPress plugins must call current_user_can() with the appropriate capability, such as manage_options, before executing privileged operations. The WP Mailgun SMTP plugin omits this check on at least one action handler, allowing any visitor to invoke the function.

Attack Vector

An attacker sends an HTTP request directly to the vulnerable plugin endpoint on the target WordPress site. No authentication, no session, and no user interaction are required. The attacker reads data exposed by the endpoint, which affects confidentiality. Integrity and availability are not impacted according to the CVSS vector.

No verified code examples are available for CVE-2025-48327. Refer to the Patchstack WP Mailgun SMTP Vulnerability advisory for further technical context.

Detection Methods for CVE-2025-48327

Indicators of Compromise

Unauthenticated HTTP requests to admin-ajax.php or plugin-specific endpoints referencing wp-mailgun-smtp actions.
Access log entries showing requests to plugin action handlers from external IP addresses without a valid wordpress_logged_in_* cookie.
Unexpected outbound connections or reconnaissance traffic targeting /wp-content/plugins/wp-mailgun-smtp/ paths.

Detection Strategies

Inventory WordPress installations and identify sites running WP Mailgun SMTP version 1.0.7 or earlier.
Enable verbose WordPress logging to capture AJAX action names, requesting user IDs, and source IP addresses.
Deploy a web application firewall rule that blocks unauthenticated invocations of the plugin's action handlers.

Monitoring Recommendations

Alert on HTTP 200 responses to wp-mailgun-smtp endpoints from clients lacking authenticated session cookies.
Track anomalous spikes in requests to admin-ajax.php with action parameters tied to the plugin.
Correlate plugin endpoint access with subsequent changes to SMTP configuration or WordPress option tables.

How to Mitigate CVE-2025-48327

Immediate Actions Required

Identify all WordPress sites running WP Mailgun SMTP <= 1.0.7 and prioritize them for remediation.
Deactivate the plugin on affected sites until a patched version is installed.
Rotate any Mailgun API credentials that may have been exposed through unauthorized access.

Patch Information

At the time of the last NVD update on 2026-06-17, no fixed version is listed in the CVE record. Monitor the Patchstack advisory and the WordPress plugin repository for a release above 1.0.7 that addresses the missing authorization check.

Workarounds

Remove or disable the WP Mailgun SMTP plugin and replace it with a maintained SMTP integration.
Restrict access to admin-ajax.php and plugin paths via web server rules or a web application firewall.
Apply virtual patching through a WordPress security plugin that blocks unauthenticated calls to wp-mailgun-smtp actions.

bash

# Example nginx rule to block unauthenticated access to the plugin directory
location ~* /wp-content/plugins/wp-mailgun-smtp/ {
    deny all;
    return 403;
}