CVE-2026-1242 in BlockSpare Plugin
Summary
by MITRE • 09/19/2026
The BlockSpare plugin for WordPress is vulnerable to authorization bypass due to incorrect logic in the permission callback in all versions up to, and including, 4.2.6 due to the use of an AND (&&) operator instead of an OR (||) operator. This makes it possible for authenticated attackers, with Subscriber-level access and above, to bypass authorization checks and create arbitrary posts.
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Analysis
by VulDB Data Team • 09/19/2026
The BlockSpare plugin for WordPress contains a critical authentication and authorization flaw that allows users with low-privilege accounts to perform administrative actions. Specifically, the vulnerability stems from an incorrect logical operator used within the permission callback function responsible for validating user capabilities before allowing access to specific endpoints or features. In versions up through 4.2.6, the code utilizes a logical AND (&&) operator where a logical OR (||) operator is required. This fundamental logic error fundamentally alters how WordPress evaluates whether a user has sufficient permissions to execute a given action. Instead of requiring that multiple conditions be met simultaneously in a way that restricts access appropriately, the flawed logic permits execution if any one of several insufficiently restrictive conditions is satisfied, effectively bypassing the intended security controls.
This vulnerability falls under the category of Broken Access Control, which corresponds to CWE-269 in the Common Weakness Enumeration standard. The specific technical manifestation involves improper privilege management where the application fails to enforce proper authorization checks for elevated functionality. By using an AND operator instead of an OR, the code likely creates a scenario where users who do not possess the necessary administrative rights can still trigger actions reserved for higher-privilege roles. This is particularly dangerous in WordPress environments because it allows authenticated attackers with Subscriber-level access and above to escalate their privileges effectively without needing to exploit separate authentication flaws or steal credentials from administrators.
The operational impact of this vulnerability is significant, as it enables unauthorized creation of arbitrary posts within the WordPress installation. An attacker leveraging this flaw can inject malicious content, deface websites, or use the platform for spamming purposes. Furthermore, depending on how the plugin integrates with other systems, such unrestricted post creation could serve as a vector for further attacks, including cross-site scripting if user input is not properly sanitized before display, although the primary issue here remains the authorization bypass itself. This undermines the integrity of the content management system and can lead to data loss or reputational damage for site owners who rely on WordPress for their online presence.
To mitigate this risk, immediate action is required by updating the BlockSpare plugin to a version newer than 4.2.6 where the logical operator has been corrected to properly enforce authorization checks. Site administrators should verify that all plugins are up to date and regularly audit user roles and capabilities within WordPress to ensure no unauthorized users have excessive permissions. Additionally, implementing Web Application Firewalls can provide an additional layer of defense by monitoring for unusual patterns in post creation requests from low-privilege accounts. Adhering to the principle of least privilege ensures that even if such vulnerabilities exist, their impact is minimized by restricting what lower-level users are allowed to do within the application environment.