CVE-2025-31025 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the Blocksera Image Hover Effects Block plugin up to version 1.4.5. This vulnerability arises due to improper neutralization of input during web page generation, allowing malicious actors to inject and store arbitrary scripts within the plugin's data inputs. When a victim loads a page containing the malicious payload, the script executes in their browser context. The vulnerability requires low privileges (PR:L) but does require user interaction (UI:R) to trigger the exploit. The attack vector is network-based (AV:N), meaning exploitation can be attempted remotely. The vulnerability impacts confidentiality, integrity, and availability to a limited extent (C:L/I:L/A:L) and has a CVSS 3.1 base score of 6.5, indicating a medium severity level. The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component, potentially impacting the broader application or site. No known exploits are currently in the wild, and no patches have been published yet. Stored XSS vulnerabilities are particularly dangerous because they can be used to steal user credentials, hijack sessions, deface websites, or deliver malware. Given the plugin’s role in enhancing image hover effects, the vulnerability likely resides in user-controllable fields such as image titles, descriptions, or hover effect parameters that are not properly sanitized before rendering. Attackers with at least low-level privileges on the affected system can inject malicious scripts that persist and affect other users visiting the site.

For European organizations, this vulnerability poses a significant risk especially for those relying on WordPress or similar CMS platforms that utilize the Blocksera Image Hover Effects Block plugin. Exploitation could lead to unauthorized disclosure of sensitive user information, session hijacking, and potential defacement or malware distribution through trusted websites. This can damage organizational reputation, lead to regulatory non-compliance under GDPR due to data breaches, and cause operational disruptions. Since the vulnerability requires low privileges but user interaction, insider threats or compromised accounts could be leveraged to inject malicious scripts. The scope change means that the impact can extend beyond the plugin itself, potentially affecting the entire website or application, increasing the risk surface. European organizations in sectors such as e-commerce, media, education, and government that use this plugin are particularly at risk. Furthermore, the lack of available patches increases the urgency for mitigation to prevent exploitation.

1. Immediate mitigation should include disabling or removing the Blocksera Image Hover Effects Block plugin until a security patch is released. 2. Implement strict input validation and output encoding on all user-supplied data fields related to the plugin, ensuring that any HTML or JavaScript content is properly sanitized. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected web pages. 4. Monitor web application logs for unusual input patterns or script injections related to the plugin. 5. Restrict user privileges to the minimum necessary to reduce the risk of malicious input injection. 6. Educate administrators and users about the risks of clicking on suspicious links or interacting with untrusted content. 7. Once a patch is available, promptly apply it and verify the fix through security testing. 8. Consider deploying Web Application Firewalls (WAF) with rules targeting XSS payloads specific to this plugin’s context to provide an additional layer of defense.