CVE-2025-6324 is a DOM-based Cross-site Scripting (XSS) vulnerability affecting MatrixAddons Easy Invoice software versions up to 2.0.9. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, allowing malicious scripts to be injected and executed in the victim's browser environment. This type of XSS occurs on the client side, where the malicious payload is executed as part of the Document Object Model (DOM) manipulation, rather than being directly reflected or stored on the server. The vulnerability does not require authentication (PR:N) but does require user interaction (UI:R), such as clicking a crafted link or visiting a malicious page that triggers the payload. The CVSS vector indicates network attack vector (AV:N), low attack complexity (AC:L), and a scope change (S:C), meaning the vulnerability can affect components beyond the initially vulnerable module. The impact includes partial loss of confidentiality, integrity, and availability (C:L/I:L/A:L), as attackers can steal session tokens, manipulate displayed data, or cause denial of service. No patches or known exploits are currently publicly available, but the vulnerability is published and should be addressed promptly. The affected product, Easy Invoice, is used primarily by small and medium enterprises (SMEs) for invoicing and financial record management, making the confidentiality and integrity of data critical. The vulnerability's exploitation could lead to unauthorized access to sensitive financial data, fraudulent invoice manipulation, or broader network compromise if attackers leverage the XSS to pivot further. The vulnerability was reserved in June 2025 and published in December 2025, indicating recent discovery and disclosure.

For European organizations, especially SMEs relying on Easy Invoice for financial operations, this vulnerability poses a significant risk. Exploitation could lead to theft of sensitive financial data, including client details and invoice information, potentially resulting in financial fraud or regulatory non-compliance under GDPR. The integrity of invoicing data could be compromised, leading to falsified invoices or altered payment instructions, which can cause financial losses and reputational damage. Additionally, attackers could hijack user sessions or perform actions on behalf of legitimate users, escalating the attack impact. The availability impact, while partial, could disrupt invoicing workflows, affecting business continuity. Given the interconnected nature of European business ecosystems, a successful attack could have cascading effects on supply chains and partner organizations. The requirement for user interaction means phishing or social engineering campaigns could be used to trigger exploitation, increasing the threat surface. The lack of known exploits in the wild currently reduces immediate risk but does not eliminate the potential for rapid weaponization following public disclosure.

Organizations should prioritize applying security patches from MatrixAddons as soon as they become available. In the absence of patches, implement strict input validation and output encoding on all user-controllable inputs within Easy Invoice to prevent malicious script injection. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS payloads. Conduct user awareness training to recognize and avoid phishing attempts that could trigger the vulnerability. Regularly audit and monitor web application logs for suspicious activities indicative of XSS exploitation attempts. Consider using web application firewalls (WAFs) with rules tailored to detect and block XSS payloads targeting Easy Invoice. Segregate the invoicing system network segment to limit lateral movement in case of compromise. Finally, maintain up-to-date backups of invoicing data to ensure recovery in case of data integrity or availability issues.