CVE-2025-26867 is a security vulnerability classified under CWE-862 (Missing Authorization) affecting the Themes4WP Bulk plugin, versions up to 1.0.11. This vulnerability arises due to insufficient access control mechanisms, allowing unauthorized users to access functionality that should be restricted by Access Control Lists (ACLs). Specifically, the issue permits unauthenticated remote attackers to invoke certain functions within the Bulk plugin without proper authorization checks. The vulnerability is remotely exploitable over the network without requiring any privileges or user interaction, as indicated by the CVSS vector (AV:N/AC:L/PR:N/UI:N). Although the vulnerability does not impact confidentiality or availability, it compromises the integrity of the affected system by allowing unauthorized modification or manipulation of data or settings within the plugin's scope. The CVSS v3.1 base score is 5.3, categorizing it as a medium severity issue. No patches or fixes have been published at the time of this report, and there are no known exploits in the wild. The vulnerability was reserved in February 2025 and published in May 2025, indicating recent discovery and disclosure. Themes4WP Bulk is a WordPress plugin, and such plugins are commonly used to manage or bulk edit themes or related content in WordPress environments. The missing authorization flaw could allow attackers to perform unauthorized administrative or configuration actions, potentially leading to further compromise if leveraged in a chained attack scenario.

For European organizations, the impact of CVE-2025-26867 depends largely on the extent of Themes4WP Bulk plugin deployment within their WordPress infrastructure. Organizations using this plugin may face unauthorized modifications to their website themes or configurations, which could lead to defacement, insertion of malicious content, or disruption of normal site operations. While the vulnerability does not directly expose sensitive data or cause denial of service, unauthorized integrity modifications can undermine trust, damage brand reputation, and potentially serve as a foothold for further attacks such as privilege escalation or malware deployment. Given the widespread use of WordPress across European businesses, especially in SMEs and public sector websites, exploitation could have a moderate operational impact. Additionally, organizations subject to strict data protection regulations like GDPR must consider the reputational and compliance risks associated with unauthorized website modifications. The lack of authentication requirement increases the risk profile, as attackers can exploit the vulnerability without prior access.

1. Immediate mitigation involves disabling or removing the Themes4WP Bulk plugin until an official patch or update is released by the vendor. 2. Monitor WordPress installations for unusual activity or unauthorized changes in themes or plugin configurations. 3. Implement Web Application Firewalls (WAFs) with custom rules to detect and block suspicious requests targeting the Bulk plugin endpoints. 4. Restrict access to WordPress admin interfaces and plugin functionalities via IP whitelisting or VPN access where feasible. 5. Regularly audit user roles and permissions within WordPress to ensure least privilege principles are enforced. 6. Stay updated with vendor announcements and apply patches promptly once available. 7. Employ security plugins that can detect unauthorized changes or file modifications in WordPress environments. 8. Conduct penetration testing focusing on authorization controls in WordPress plugins to identify similar weaknesses proactively.