CVE-2025-46536 is a DOM-based Cross-site Scripting (XSS) vulnerability identified in the RichardHarrison Carousel-of-post-images plugin, specifically affecting versions up to 1.07. This vulnerability arises due to improper neutralization of input during web page generation, classified under CWE-79. DOM-based XSS occurs when client-side scripts write untrusted data to the Document Object Model (DOM) without proper sanitization or encoding, enabling attackers to inject malicious scripts that execute in the context of the victim's browser. In this case, the Carousel-of-post-images plugin fails to adequately sanitize user-controllable input before rendering it on the page, allowing an attacker to craft a malicious URL or input that, when processed by the plugin, results in arbitrary JavaScript execution. This can lead to session hijacking, credential theft, unauthorized actions on behalf of the user, or distribution of malware. The vulnerability does not require server-side injection but exploits client-side scripting logic, making it particularly dangerous in environments where the plugin is widely used and trusted. No patches or fixes have been published at the time of this analysis, and no known exploits are currently observed in the wild. However, the presence of this vulnerability in a popular WordPress plugin component used for displaying image carousels on posts means that many websites leveraging this plugin could be at risk if they do not implement additional mitigations or updates once available.

For European organizations, the impact of this DOM-based XSS vulnerability can be significant, especially for entities relying on WordPress websites that use the Carousel-of-post-images plugin for content presentation. Exploitation could lead to compromise of user sessions, leakage of sensitive data such as authentication tokens or personal information, and unauthorized actions performed on behalf of legitimate users. This is particularly critical for organizations handling personal data under GDPR, as exploitation could result in data breaches with legal and financial consequences. Additionally, compromised websites could be used to distribute malware or phishing content, damaging brand reputation and trust. Sectors such as e-commerce, media, education, and government agencies that maintain public-facing WordPress sites are at heightened risk. The vulnerability's client-side nature means that attacks can be triggered by simply tricking users into visiting a maliciously crafted URL, increasing the attack surface. While no active exploits are reported, the medium severity rating suggests a moderate risk that could escalate if weaponized. The lack of a patch increases exposure time, emphasizing the need for proactive defenses.

Given the absence of an official patch, European organizations should implement several practical mitigations: 1) Employ Content Security Policy (CSP) headers with strict script-src directives to restrict execution of unauthorized scripts and reduce the impact of injected code. 2) Use web application firewalls (WAFs) configured to detect and block suspicious input patterns targeting the Carousel-of-post-images plugin, focusing on typical XSS payload signatures. 3) Conduct thorough input validation and output encoding on any user-controllable parameters that interact with the plugin, if custom integrations exist. 4) Monitor website logs and user reports for unusual behavior or complaints related to script execution anomalies. 5) Educate users and administrators about the risks of clicking unknown or suspicious links that could exploit DOM-based XSS. 6) Plan for rapid deployment of updates once the vendor releases a patch, including testing in staging environments to ensure compatibility. 7) Consider temporarily disabling or replacing the vulnerable plugin with alternative solutions that have a stronger security posture until a fix is available. These steps go beyond generic advice by focusing on specific controls tailored to the plugin's client-side scripting context and the operational environment of affected organizations.