CVE-2026-0594 is a reflected Cross-Site Scripting (XSS) vulnerability identified in the List Site Contributors plugin for WordPress, specifically affecting versions up to and including 1.1.8. The vulnerability stems from improper neutralization of input during web page generation, classified under CWE-79. The 'alpha' parameter is not sufficiently sanitized or escaped before being reflected in the web page output, allowing an unauthenticated attacker to craft a malicious URL containing executable JavaScript code. When a victim clicks this link, the injected script executes in the context of the victim's browser session, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the user. The vulnerability does not require authentication but does require user interaction (clicking a malicious link). The CVSS v3.1 base score is 6.1, reflecting a medium severity with network attack vector, low attack complexity, no privileges required, user interaction required, and a scope change due to impact on confidentiality and integrity but not availability. No known exploits have been reported in the wild as of the publication date. The plugin is used to list contributors on WordPress sites, which are common in community, e-commerce, and content-driven websites. The vulnerability's exploitation could undermine user trust and lead to data leakage or unauthorized actions within affected sites.

For European organizations, the impact of CVE-2026-0594 can be significant, particularly for those relying on WordPress sites with the List Site Contributors plugin installed. Exploitation could lead to theft of user credentials, session tokens, or other sensitive information, compromising user accounts and potentially allowing attackers to escalate privileges or perform unauthorized transactions. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR violations due to data leakage), and cause operational disruptions if attackers leverage stolen credentials for further attacks. Public-facing websites with high user interaction or e-commerce functionality are especially vulnerable. Although availability is not directly impacted, the confidentiality and integrity breaches can have cascading effects on business continuity and customer trust. The lack of known exploits in the wild reduces immediate risk but does not eliminate the threat, as attackers may develop exploits once the vulnerability becomes widely known.

1. Monitor for an official patch or update from the plugin vendor and apply it promptly once available. 2. Until a patch is released, implement web application firewall (WAF) rules to detect and block malicious payloads targeting the 'alpha' parameter. 3. Employ strict input validation and output encoding on the 'alpha' parameter within the plugin code if feasible, to neutralize malicious scripts. 4. Educate users and administrators about the risks of clicking untrusted links, especially those referencing the affected plugin's parameters. 5. Conduct regular security audits and vulnerability scans on WordPress sites to identify outdated or vulnerable plugins. 6. Consider disabling or replacing the List Site Contributors plugin with a more secure alternative if immediate patching is not possible. 7. Implement Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 8. Monitor logs for suspicious activities that may indicate attempted exploitation.