CVE-2025-67556 is a Stored Cross-Site Scripting (XSS) vulnerability identified in the ThemeHigh Advanced FAQ Manager plugin, affecting versions up to and including 1.5.2. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, which allows malicious scripts to be stored and later executed in the context of users viewing the affected pages. Stored XSS is particularly dangerous because the malicious payload persists on the server and can affect multiple users. According to the CVSS vector (CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L), the attack requires network access, low attack complexity, high privileges (such as administrator or editor roles), and user interaction (victim must trigger the malicious script by visiting a crafted page). The scope is changed, meaning the vulnerability can affect resources beyond the initially vulnerable component. The impact includes limited confidentiality loss (e.g., theft of session cookies or sensitive data accessible to the user), integrity loss (e.g., manipulation of displayed content), and availability loss (e.g., potential denial of service through script execution). No public exploits are currently known, and no patches have been linked yet. The vulnerability was published on December 9, 2025, and assigned by Patchstack. The affected product is a WordPress plugin commonly used to manage FAQs on websites, which may be widely deployed in various organizational websites.

For European organizations, the impact of this vulnerability depends on the extent of usage of the ThemeHigh Advanced FAQ Manager plugin within their web infrastructure. Organizations using this plugin with administrative users exposed to the internet are at risk of attackers injecting malicious scripts that could compromise user sessions, steal sensitive information, or manipulate website content. This can lead to reputational damage, data breaches, and potential regulatory non-compliance under GDPR if personal data is exposed. The requirement for high privileges and user interaction limits the ease of exploitation but does not eliminate risk, especially in environments with multiple administrators or editors. Attackers could leverage this vulnerability to pivot to further attacks within the network or to target customers and partners. The medium severity rating reflects a moderate threat level but should not be underestimated given the persistence and potential for chained attacks. Organizations in sectors such as finance, healthcare, and government, which often have strict data protection requirements, may face heightened consequences.

1. Monitor ThemeHigh’s official channels for security patches addressing CVE-2025-67556 and apply updates promptly once available. 2. Until patches are released, restrict administrative and editor privileges to trusted personnel only, minimizing the number of users who can input content that might be exploited. 3. Implement strong input validation and sanitization on all user inputs, especially those that are stored and rendered on web pages. 4. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of XSS attacks. 5. Conduct regular security audits and penetration testing focused on web application vulnerabilities, including stored XSS. 6. Educate administrators and content managers about the risks of clicking on suspicious links or interacting with untrusted content. 7. Use Web Application Firewalls (WAFs) configured to detect and block common XSS attack patterns targeting the affected plugin. 8. Review and harden WordPress security configurations, including limiting plugin installations to those that are actively maintained and vetted.