CVE-2025-39591 Overview
CVE-2025-39591 is a missing authorization vulnerability in the WP Shuffle WP Subscription Forms plugin for WordPress. The flaw affects all versions of the wp-subscription-forms plugin up to and including 1.2.3. The plugin exposes functionality protected by incorrectly configured access control, allowing authenticated users with low privileges to perform actions they should not be permitted to execute. The vulnerability is classified under CWE-862: Missing Authorization.
Critical Impact
Authenticated attackers with minimal privileges can bypass access controls in the WP Subscription Forms plugin, leading to limited integrity and availability impact on affected WordPress sites.
Affected Products
- WP Shuffle WP Subscription Forms plugin (wp-subscription-forms)
- All versions from initial release through 1.2.3
- WordPress sites running the affected plugin versions
Discovery Timeline
- 2025-04-16 - CVE-2025-39591 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-39591
Vulnerability Analysis
The vulnerability stems from missing authorization checks in the WP Subscription Forms plugin. The plugin exposes actions or endpoints that fail to verify whether the requesting user holds the required capability or role before executing privileged operations. This design flaw enables users authenticated at low privilege levels to invoke functionality intended for administrators or higher-privileged roles.
The issue is exploitable over the network without user interaction. An attacker needs only low-privileged authenticated access, such as a subscriber account, which is often obtainable through open registration on many WordPress deployments. Successful exploitation can lead to unauthorized modification of plugin data and limited disruption of availability, though confidentiality remains unaffected. The Patchstack Vulnerability Report provides additional context on the affected component.
Root Cause
The root cause is broken access control within the plugin's request handlers. Specifically, the plugin does not consistently validate user capabilities using WordPress functions such as current_user_can() before executing sensitive actions. Nonce validation and role-based checks are either absent or improperly implemented on affected endpoints.
Attack Vector
An authenticated attacker sends a crafted HTTP request to the vulnerable plugin endpoint. Because the endpoint does not enforce authorization checks, the request is processed under the attacker's low-privilege session. The vulnerability manifests as broken access control in the plugin's AJAX or admin-post handlers. See the Patchstack advisory for exploitation specifics.
// No verified public exploit code is available for this vulnerability.
// Refer to the Patchstack advisory for technical exploitation details.
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Stop Identity AttacksDetection Methods for CVE-2025-39591
Indicators of Compromise
- Unexpected modifications to subscription form configurations or subscriber lists in the WordPress database
- HTTP POST requests to wp-admin/admin-ajax.php or plugin-specific endpoints originating from low-privilege user sessions
- New or altered plugin settings that do not correspond to administrator activity in the WordPress audit log
Detection Strategies
- Review WordPress access logs for requests to wp-subscription-forms endpoints made by users with subscriber or contributor roles
- Deploy a web application firewall (WAF) rule to flag unauthorized access attempts to plugin AJAX actions
- Correlate plugin activity with user role information to identify capability mismatches
Monitoring Recommendations
- Enable WordPress activity logging plugins to capture administrative actions and user role changes
- Monitor for unusual authentication patterns and privilege usage across low-privilege accounts
- Alert on any plugin configuration changes performed outside of scheduled administrator maintenance windows
How to Mitigate CVE-2025-39591
Immediate Actions Required
- Update the WP Subscription Forms plugin to a version newer than 1.2.3 as soon as a patched release is available from the vendor
- Audit all existing user accounts and disable or remove accounts that do not require access
- Restrict WordPress user registration if not required for site operation
Patch Information
At the time of publication, the vulnerability affects WP Subscription Forms versions up to and including 1.2.3. Site administrators should consult the Patchstack Vulnerability Report for the latest remediation guidance and to confirm the availability of a fixed release from WP Shuffle.
Workarounds
- Deactivate and remove the WP Subscription Forms plugin until a patched version is installed
- Apply WAF rules to block requests to the vulnerable plugin endpoints from non-administrator users
- Enforce strict capability checks at the reverse proxy or application layer to prevent unauthorized action invocation
# Example: Disable the plugin using WP-CLI until a patch is available
wp plugin deactivate wp-subscription-forms
wp plugin delete wp-subscription-forms
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
