CVE-2025-10140 identifies a stored cross-site scripting vulnerability in the Quick Social Login plugin for WordPress, developed by andreiigna. The vulnerability arises from improper neutralization of user-supplied input in the 'quick-login' shortcode, which fails to adequately sanitize and escape attributes before rendering them on web pages. This flaw allows authenticated users with contributor-level permissions or higher to inject arbitrary JavaScript code into pages. Because the malicious script is stored, it executes every time any user accesses the infected page, enabling attackers to perform actions such as session hijacking, cookie theft, or redirecting users to malicious sites. The vulnerability affects all versions up to and including 1.4.6. The CVSS 3.1 base score is 6.4, with an attack vector of network (remote exploitation), low attack complexity, requiring privileges (contributor or above), no user interaction, and a scope change, indicating that the vulnerability can affect resources beyond the initially compromised component. Although no public exploits have been reported yet, the vulnerability's characteristics make it a credible threat, especially in environments where multiple users have contributor access. The lack of a patch link suggests that a fix may not yet be available, underscoring the need for interim mitigations. The vulnerability is categorized under CWE-79, which is a common and well-understood class of web application security issues.

For European organizations, this vulnerability poses a significant risk to websites using the Quick Social Login plugin, particularly those with multiple contributors or editors who have elevated permissions. Exploitation could lead to unauthorized script execution, compromising user sessions, stealing sensitive data, or defacing websites. This can damage organizational reputation, lead to data breaches involving personal data protected under GDPR, and cause operational disruptions. Since the vulnerability allows scope change, attackers might leverage it to escalate privileges or pivot to other parts of the web application. The impact is amplified in sectors with high regulatory scrutiny and public-facing websites, such as government, finance, healthcare, and e-commerce. Additionally, the stored nature of the XSS means that the malicious payload persists, increasing the window of exposure. The absence of known exploits currently provides a limited window for proactive defense before potential attackers develop weaponized code.

European organizations should immediately audit their WordPress installations to identify the presence of the Quick Social Login plugin and verify the version in use. Until a patch is released, restrict contributor-level access to trusted users only and review user permissions to minimize the number of users who can inject content. Implement web application firewalls (WAFs) with rules to detect and block typical XSS payloads targeting shortcode parameters. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts. Conduct manual or automated scanning of pages using the 'quick-login' shortcode to detect injected scripts. Encourage plugin developers or site administrators to sanitize and escape all user inputs rigorously, especially shortcode attributes. Monitor security advisories for updates or patches and apply them promptly once available. Additionally, educate content contributors about safe input practices and the risks of injecting untrusted content. Regular backups and incident response plans should be in place to recover quickly from any compromise.