CVE-2026-1310: Elementor Calendar Auth Bypass Vulnerability

CVE-2026-1310 Overview

CVE-2026-1310 is a Missing Authorization vulnerability affecting the Simple Calendar for Elementor plugin for WordPress. This security flaw exists in all versions up to and including 1.6.6, where the miga_ajax_editor_cal_delete function lacks proper capability checks. The function is hooked to the miga_editor_cal_delete AJAX action with both authenticated and unauthenticated access enabled, allowing remote attackers to delete arbitrary calendar entries without authorization.

Critical Impact

Unauthenticated attackers can delete arbitrary calendar entries by sending crafted requests with a valid nonce and calendar entry ID, potentially causing data loss and service disruption for affected WordPress sites.

Affected Products

• Simple Calendar for Elementor WordPress Plugin versions up to and including 1.6.6

Discovery Timeline

• 2026-01-28 - CVE-2026-1310 published to NVD
• 2026-01-29 - Last updated in NVD database

Technical Details for CVE-2026-1310

Vulnerability Analysis

This vulnerability falls under CWE-862 (Missing Authorization), which occurs when a software application does not perform authorization checks on a resource or function before granting access. In the case of CVE-2026-1310, the miga_ajax_editor_cal_delete function in the Simple Calendar for Elementor plugin fails to verify that the requesting user has appropriate permissions to delete calendar entries.

The vulnerable code is located in the backend_functions.php file, where the AJAX handler processes deletion requests without validating user capabilities. While the function may check for a valid nonce (which provides CSRF protection), nonces alone are insufficient for authorization since they only verify that a request originated from a legitimate WordPress session, not that the user has permission to perform the action.

Root Cause

The root cause of this vulnerability is the absence of capability checks in the miga_ajax_editor_cal_delete function. WordPress plugins should use functions like current_user_can() to verify that the logged-in user has appropriate permissions (such as edit_posts or a custom capability) before executing sensitive operations like deleting content. The function is registered to handle AJAX requests from both authenticated and unauthenticated users, compounding the security risk.

Attack Vector

The attack leverages the network-accessible AJAX endpoint exposed by WordPress. An unauthenticated attacker can exploit this vulnerability by:

1. Identifying the AJAX action endpoint (wp-admin/admin-ajax.php)
2. Obtaining or predicting a valid nonce value (which may be exposed in page source or JavaScript)
3. Crafting a malicious POST request with the action parameter set to miga_editor_cal_delete
4. Including the target calendar entry ID and nonce in the request
5. Sending the request to delete arbitrary calendar entries

The vulnerability exploitation is described in detail in the Wordfence Vulnerability Report. The WordPress Plugin Backend Functions source code shows the vulnerable function implementation.

Detection Methods for CVE-2026-1310

Indicators of Compromise

• Unexpected deletion of calendar entries in the Simple Calendar for Elementor plugin
• HTTP POST requests to admin-ajax.php with action parameter miga_editor_cal_delete from external or unauthorized sources
• Unusual volume of AJAX requests targeting calendar deletion functionality
• Missing calendar data without corresponding administrative activity in WordPress logs

Detection Strategies

• Monitor WordPress AJAX logs for requests containing the miga_editor_cal_delete action
• Implement Web Application Firewall (WAF) rules to detect and block unauthorized AJAX deletion requests
• Review access logs for patterns of POST requests to admin-ajax.php from unauthenticated sessions
• Deploy file integrity monitoring to detect unauthorized modifications to plugin files

Monitoring Recommendations

• Enable comprehensive WordPress logging to capture all AJAX requests and their source IPs
• Configure alerts for unusual patterns of calendar entry deletions
• Implement rate limiting on AJAX endpoints to mitigate automated exploitation attempts
• Regularly audit calendar content to identify unauthorized deletions

How to Mitigate CVE-2026-1310

Immediate Actions Required

• Update the Simple Calendar for Elementor plugin to a version newer than 1.6.6 that includes the security fix
• Review WordPress access logs for any evidence of exploitation
• Restore any deleted calendar entries from backups if exploitation has occurred
• Temporarily disable the plugin if an update is not immediately available

Patch Information

The vulnerability has been addressed in versions after 1.6.6. Security researchers can review the changes in the WordPress Plugin Change Log. Users should update to the latest available version through the WordPress admin dashboard or by downloading directly from the WordPress plugin repository.

Workarounds

• Restrict access to admin-ajax.php for unauthenticated users if calendar functionality is not required for public visitors
• Implement additional server-level access controls to limit AJAX endpoint exposure
• Use a Web Application Firewall to filter malicious requests targeting the vulnerable AJAX action
• Consider temporarily deactivating the Simple Calendar for Elementor plugin until the update can be applied

# Configuration example - Restrict AJAX access via .htaccess (Apache)
# Add to WordPress root .htaccess file
<Files admin-ajax.php>
    <RequireAny>
        Require ip 127.0.0.1
        Require ip ::1
        # Add your authorized IP addresses
    </RequireAny>
</Files>