CVE-2026-57813 in MailOptin Plugin
Summary
by MITRE • 07/13/2026
Incorrect Privilege Assignment vulnerability in properfraction MailOptin mailoptin allows Privilege Escalation.This issue affects MailOptin: from n/a through <= 1.2.77.3.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 07/13/2026
This vulnerability represents an incorrect privilege assignment flaw that enables privilege escalation within the properfraction MailOptin plugin for WordPress. The issue stems from improper access control mechanisms that allow unauthorized users to gain elevated privileges, potentially leading to complete system compromise. The vulnerability affects versions up to and including 1.2.77.3, indicating a significant window of exposure for affected systems.
The technical root cause involves the plugin's insufficient validation of user permissions during privilege assignment operations. When users interact with certain administrative functions, the system fails to properly verify whether the requesting user possesses adequate authorization levels. This misconfiguration creates a pathway for low-privilege attackers to manipulate session data or exploit API endpoints that should be restricted to administrators only.
From an operational perspective, this vulnerability poses severe risks to WordPress installations using the affected MailOptin plugin. An attacker with minimal privileges could potentially escalate their access to administrator level accounts, gaining complete control over the website's functionality, user data, and content management capabilities. The impact extends beyond individual sites to encompass potential data breaches, defacement operations, and establishment of persistent backdoors within the compromised environment.
The vulnerability aligns with CWE-276, which specifically addresses incorrect privilege assignment in software systems. This classification emphasizes the fundamental security flaw where system components fail to properly enforce access controls that should restrict user capabilities based on their assigned roles. Additionally, this issue maps to ATT&CK technique T1078 which covers legitimate credentials usage and privilege escalation through improper access control mechanisms.
Effective mitigation strategies include immediate patching of the MailOptin plugin to version 1.2.77.4 or later, which addresses the privilege assignment flaw. System administrators should also implement additional security measures such as role-based access control restrictions, regular monitoring of user activities, and implementation of web application firewalls that can detect anomalous privilege escalation attempts. Network segmentation and least-privilege principles should be enforced to minimize potential damage from successful exploitation attempts.
Organizations using this plugin should conduct thorough security assessments of their WordPress installations, reviewing all active plugins for similar access control vulnerabilities. Regular security audits and vulnerability scanning should be implemented as part of ongoing security monitoring practices. The incident highlights the critical importance of proper privilege management in web applications and demonstrates how seemingly minor access control flaws can result in significant security breaches. Immediate remediation is essential to protect against potential exploitation attempts and maintain system integrity across affected installations.