CVE-2025-9858 is a Stored Cross-Site Scripting (XSS) vulnerability identified in the Auto Bulb Finder plugin for WordPress, developed by mtoolstec. This vulnerability affects all versions up to and including 2.8.0 of the plugin. The root cause is improper neutralization of input during web page generation, specifically insufficient sanitization and output escaping of user-supplied attributes in the 'abf_vehicle' shortcode. An authenticated attacker with contributor-level access or higher can exploit this flaw by injecting malicious JavaScript payloads into pages or posts using the vulnerable shortcode. When other users visit these pages, the injected scripts execute in their browsers, potentially leading to session hijacking, privilege escalation, defacement, or distribution of malware. The vulnerability does not require user interaction beyond visiting the compromised page and does not require elevated privileges beyond contributor-level access, which is commonly granted to trusted users who can create or edit content. The CVSS v3.1 base score is 6.4, reflecting a medium severity level, with an attack vector of network, low attack complexity, privileges required at the contributor level, no user interaction needed, and a scope change due to impact on other users. Confidentiality and integrity are impacted, but availability is not affected. No known exploits in the wild have been reported yet, and no official patches have been linked at the time of publication. This vulnerability highlights the importance of rigorous input validation and output encoding in WordPress plugins, especially those that allow user-generated content or shortcode attributes.

For European organizations using WordPress websites with the Auto Bulb Finder plugin installed, this vulnerability poses a significant risk to website integrity and user trust. Attackers with contributor-level access—often internal users or compromised accounts—can inject malicious scripts that execute in the browsers of site visitors, including customers, partners, or employees. This can lead to theft of authentication cookies, unauthorized actions performed on behalf of users, defacement of web content, or distribution of malware. The impact is particularly critical for e-commerce, governmental, and financial sector websites where user data confidentiality and integrity are paramount. Additionally, the scope change in the vulnerability means that the attacker can affect users beyond their own privileges, potentially compromising administrators or other privileged users. Given the widespread use of WordPress in Europe and the common practice of granting contributor access to multiple users, the risk of exploitation is non-trivial. Furthermore, GDPR compliance may be impacted if personal data is exposed or manipulated through such attacks, leading to regulatory and reputational consequences.

European organizations should immediately audit their WordPress installations to identify if the Auto Bulb Finder plugin is in use and determine the version. Until an official patch is released, mitigation should include: 1) Restricting contributor-level access strictly to trusted users and reviewing user roles and permissions to minimize the number of users with content editing capabilities. 2) Implementing Web Application Firewall (WAF) rules that detect and block suspicious shortcode attribute inputs or script injection patterns targeting the 'abf_vehicle' shortcode. 3) Employing Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected sites. 4) Monitoring website content for unexpected script injections or changes, using file integrity monitoring and security plugins that scan for XSS payloads. 5) Educating content contributors about the risks of injecting untrusted code and encouraging secure content practices. Once a patch is available, organizations must prioritize updating the plugin to the fixed version. Additionally, consider isolating or disabling the vulnerable shortcode if it is not essential to site functionality.