CVE-2026-1885 identifies a stored cross-site scripting (XSS) vulnerability in the Slideshow Wp plugin for WordPress, specifically affecting all versions up to and including 1.1. The vulnerability is due to improper neutralization of input during web page generation (CWE-79), where the 'sswpid' attribute of the 'sswp-slide' shortcode does not undergo sufficient input sanitization or output escaping. This flaw enables authenticated attackers with contributor-level privileges or higher to inject arbitrary JavaScript code into WordPress pages. When any user accesses a page containing the injected shortcode, the malicious script executes in their browser context, potentially allowing session hijacking, privilege escalation, or unauthorized actions within the site. The attack vector is remote over the network, with low attack complexity, requiring only contributor-level privileges and no user interaction beyond page viewing. The vulnerability affects the confidentiality and integrity of user sessions and site data but does not impact availability. The CVSS 3.1 base score is 6.4, categorized as medium severity. No patches or fixes are currently linked, and no known exploits have been reported in the wild. The vulnerability's scope is limited to WordPress sites using the Slideshow Wp plugin with affected versions, but given WordPress's widespread use, the potential attack surface is significant. The vulnerability highlights the importance of proper input validation and output encoding in plugin development to prevent stored XSS attacks.

For European organizations, this vulnerability poses a moderate risk primarily to websites running WordPress with the Slideshow Wp plugin installed. Exploitation could lead to unauthorized script execution in users' browsers, enabling session hijacking, defacement, or unauthorized actions performed under the victim's credentials. This can result in data leakage, loss of user trust, and potential regulatory compliance issues under GDPR if personal data is compromised. Organizations with contributor-level users who can edit content are at particular risk, as these accounts can be leveraged to inject malicious scripts. The impact is heightened for entities relying on WordPress for customer-facing or internal portals, including e-commerce, government, and media websites. While availability is not directly affected, the integrity and confidentiality of site content and user sessions are at risk. The absence of known exploits reduces immediate threat but does not eliminate risk, as attackers may develop exploits. European organizations must consider the reputational and legal consequences of a successful attack, especially given stringent data protection regulations.

1. Immediately restrict contributor-level user permissions to the minimum necessary, preventing unauthorized shortcode insertion. 2. Monitor and audit content changes involving the 'sswp-slide' shortcode and the 'sswpid' attribute for suspicious or unexpected modifications. 3. Implement web application firewalls (WAFs) with custom rules to detect and block malicious script injections targeting this vulnerability. 4. Apply strict input validation and output encoding in any custom code interacting with the plugin or shortcode attributes. 5. If possible, disable or remove the Slideshow Wp plugin until a vendor patch is released. 6. Educate content editors and contributors about the risks of injecting untrusted content and the importance of secure content management practices. 7. Regularly update WordPress core and plugins, and monitor vendor communications for patches addressing this vulnerability. 8. Conduct security scans and penetration tests focusing on stored XSS vectors in WordPress environments. 9. Employ Content Security Policy (CSP) headers to limit the impact of injected scripts. 10. Maintain incident response readiness to quickly address any exploitation attempts.