CVE-2026-1191 is a stored cross-site scripting (XSS) vulnerability identified in the freemp JavaScript Notifier plugin for WordPress, affecting all versions up to and including 1.2.8. The root cause is insufficient sanitization and escaping of user-supplied input within the plugin's settings, specifically during the execution of the wp_footer action hook. This flaw allows an attacker with administrator-level privileges to inject arbitrary JavaScript code into plugin settings, which is then stored persistently and executed in the browsers of any users who visit pages where the plugin outputs this data. The vulnerability leverages CWE-79, indicating improper neutralization of input during web page generation. Exploitation does not require user interaction but does require the attacker to have authenticated admin access, which limits the attack vector to insiders or compromised admin accounts. The CVSS v3.1 base score is 4.4, reflecting a medium severity with the vector AV:N/AC:H/PR:H/UI:N/S:C/C:L/I:L/A:N, meaning network attack vector, high attack complexity, high privileges required, no user interaction, scope changed, with low impact on confidentiality and integrity, and no impact on availability. No public exploits are currently known, but the vulnerability could be leveraged for session hijacking, defacement, or further attacks against site visitors. The plugin is widely used in WordPress environments, making it a relevant concern for website administrators. The lack of available patches at the time of disclosure necessitates immediate mitigation steps to reduce risk.

For European organizations, this vulnerability poses a risk primarily to the confidentiality and integrity of web applications running WordPress with the freemp JavaScript Notifier plugin installed. An attacker with administrator access could inject malicious scripts that execute in the browsers of site visitors, potentially leading to session hijacking, theft of sensitive information, or unauthorized actions performed on behalf of users. This could damage organizational reputation, lead to data breaches, and violate data protection regulations such as GDPR. Since exploitation requires admin-level access, the threat is heightened if internal accounts are compromised or if attackers gain access through phishing or credential stuffing. The vulnerability does not impact availability directly but could be a stepping stone for more severe attacks. European organizations with public-facing WordPress sites, especially those handling personal or financial data, are at increased risk. The medium severity score suggests moderate urgency, but the potential for chained attacks elevates the importance of timely remediation.

1. Immediately restrict administrator access to trusted personnel and enforce strong authentication mechanisms, including multi-factor authentication (MFA), to reduce the risk of credential compromise. 2. Audit all administrator accounts and revoke or reset credentials for any suspicious or inactive accounts. 3. Until a patch is available, disable or remove the freemp JavaScript Notifier plugin from WordPress installations to eliminate the attack vector. 4. Implement web application firewalls (WAF) with custom rules to detect and block suspicious payloads targeting the plugin's settings interface. 5. Regularly monitor logs for unusual administrator activity or changes in plugin settings that could indicate exploitation attempts. 6. Educate administrators about phishing and social engineering risks to prevent credential theft. 7. Once a patch is released, apply it promptly and verify that input sanitization and output escaping are correctly enforced. 8. Conduct security testing and code reviews on plugins before deployment to identify similar vulnerabilities proactively. 9. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected sites. 10. Maintain regular backups of website data to enable recovery in case of compromise.