CVE-2025-9876 is a stored Cross-Site Scripting (XSS) vulnerability affecting the Ird Slider plugin for WordPress, developed by inforrada. This vulnerability exists in all versions up to and including 1.0.2 of the plugin. The root cause is insufficient input sanitization and output escaping of user-supplied attributes within the 'irdslider' shortcode functionality. Authenticated users with contributor-level privileges or higher can exploit this flaw by injecting arbitrary JavaScript code into pages that utilize the vulnerable shortcode. When other users access these pages, the malicious scripts execute in their browsers, potentially leading to session hijacking, defacement, or further exploitation of the victim's environment. The vulnerability is classified under CWE-79, which pertains to improper neutralization of input during web page generation. The CVSS v3.1 base score is 6.4, indicating a medium severity level. The attack vector is network-based with low attack complexity, requiring privileges equivalent to contributor access but no user interaction from victims. The scope is changed, meaning the vulnerability can affect resources beyond the initially compromised component. No known exploits have been reported in the wild as of the publication date (October 3, 2025), and no official patches have been released yet. This vulnerability is significant because WordPress is widely used across many organizations, and plugins like Ird Slider are common for content presentation, making it a potential vector for persistent XSS attacks within trusted domains.

For European organizations, this vulnerability poses a moderate risk primarily to websites and web applications running WordPress with the Ird Slider plugin installed. The ability for authenticated contributors to inject persistent malicious scripts can lead to unauthorized actions on behalf of users, data theft, or defacement, undermining user trust and potentially violating data protection regulations such as GDPR if personal data is compromised. Since contributors typically have content creation privileges, the risk of insider threat or compromised contributor accounts increases the attack surface. The cross-site scripting can also be leveraged to escalate attacks, such as stealing authentication tokens or conducting phishing campaigns within the organization's domain. This can disrupt business operations, damage reputation, and result in regulatory penalties. The medium CVSS score reflects that while the vulnerability requires some level of authentication, the ease of exploitation and potential for scope change make it a noteworthy threat. European organizations with public-facing WordPress sites, especially those in sectors like government, finance, healthcare, and e-commerce, where trust and data integrity are critical, should be particularly vigilant.

1. Immediate mitigation should include restricting contributor-level access to trusted users only and auditing existing contributor accounts for suspicious activity. 2. Implement strict content moderation policies to review any content submitted via the 'irdslider' shortcode before publishing. 3. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious script injections targeting the shortcode parameters. 4. Use Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected pages. 5. Monitor logs for unusual activity related to shortcode usage or contributor actions. 6. Since no official patch is available yet, consider temporarily disabling or removing the Ird Slider plugin until a secure update is released. 7. Educate content creators and administrators about the risks of XSS and safe content handling practices. 8. Once a patch is available, promptly apply it and verify the fix through security testing. 9. Conduct regular vulnerability scans and penetration tests focusing on WordPress plugins to detect similar issues proactively.