CVE-2025-6815 is a stored cross-site scripting vulnerability identified in the LatePoint – Calendar Booking Plugin for Appointments and Events, a WordPress plugin widely used for managing bookings and events. The vulnerability stems from improper neutralization of input during web page generation, specifically in the 'service[name]' parameter. This parameter is insufficiently sanitized and escaped, allowing an authenticated attacker with administrator privileges to inject arbitrary JavaScript code into pages generated by the plugin. The malicious script is stored persistently and executes whenever any user visits the affected page, potentially leading to session hijacking, privilege escalation, or other malicious actions within the context of the victim's browser. The vulnerability affects all versions up to and including 5.1.94 and is limited to multisite WordPress installations or those where the 'unfiltered_html' capability is disabled, which restricts the ability of users to post unfiltered HTML. The CVSS 3.1 vector (AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:L/A:N) indicates that the attack can be performed remotely over the network with low attack complexity but requires high privileges (administrator) and no user interaction. The scope is changed, meaning the vulnerability affects resources beyond the initially vulnerable component. The impact on confidentiality and integrity is low, and availability is not affected. No public exploits have been reported yet, but the presence of this vulnerability in a popular WordPress plugin used for appointment scheduling makes it a significant concern, especially in environments where multisite configurations are common. The lack of a patch link suggests that a fix may not yet be publicly available, emphasizing the need for immediate mitigation steps.

For European organizations, the impact of CVE-2025-6815 can be significant in environments using the LatePoint plugin in multisite WordPress installations, which are common in enterprises and service providers managing multiple client sites. Exploitation could allow an attacker with administrator access to inject malicious scripts that execute in the context of other users, potentially leading to session hijacking, theft of sensitive information, or unauthorized actions performed on behalf of legitimate users. This can undermine the integrity of booking and event management systems, disrupt business operations, and damage customer trust. Since the vulnerability requires administrator privileges, the risk is somewhat mitigated by internal access controls; however, insider threats or compromised administrator accounts could be leveraged. The vulnerability does not affect availability directly but can facilitate further attacks that might. Given the widespread use of WordPress and the popularity of booking plugins in sectors like healthcare, education, and professional services across Europe, the potential for targeted exploitation exists. Additionally, multisite configurations are often used by agencies and large organizations, increasing the attack surface. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers often develop exploits post-disclosure. Organizations failing to address this vulnerability may face regulatory scrutiny under GDPR if personal data is compromised through such attacks.

1. Immediately verify if your WordPress environment uses the LatePoint plugin in a multisite configuration or with unfiltered_html disabled. 2. Restrict administrator access strictly to trusted personnel and enforce strong authentication mechanisms, including multi-factor authentication (MFA). 3. Monitor and audit administrator activities to detect any suspicious input or script injection attempts. 4. Apply any available patches or updates from the LatePoint vendor as soon as they are released; if no patch is available, consider temporarily disabling the plugin or restricting its use in multisite contexts. 5. Implement Web Application Firewall (WAF) rules to detect and block malicious payloads targeting the 'service[name]' parameter. 6. Harden WordPress security by limiting plugin installations, disabling unnecessary features, and ensuring that user roles and capabilities are properly configured. 7. Educate administrators about the risks of injecting untrusted input and the importance of input validation. 8. Regularly back up WordPress sites and test restoration procedures to recover quickly from potential compromises. 9. Consider deploying Content Security Policy (CSP) headers to reduce the impact of XSS attacks by restricting script execution sources. 10. Conduct security assessments and penetration testing focused on multisite WordPress environments to identify similar vulnerabilities.