CVE-2025-58648 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the Simple JWT Login plugin developed by Nicu Micle. This vulnerability arises from improper neutralization of input during web page generation, allowing malicious scripts to be stored and subsequently executed in the context of users' browsers. The affected versions include all versions up to 3.6.4, with no specific earliest affected version identified. The vulnerability has a CVSS 3.1 base score of 6.5, indicating a medium severity level. The CVSS vector (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L) reveals that the attack can be executed remotely over the network with low attack complexity, requires low privileges, and user interaction is necessary. The scope is changed, meaning the vulnerability affects resources beyond the initially vulnerable component. The impact includes limited confidentiality, integrity, and availability losses. Stored XSS vulnerabilities allow attackers to inject malicious JavaScript code that is permanently stored on the target server (e.g., in a database or message forum) and executed when other users access the affected pages. This can lead to session hijacking, credential theft, defacement, or redirection to malicious sites. The Simple JWT Login plugin is typically used in web applications to manage JSON Web Token-based authentication, making it a critical component in user authentication flows. Exploitation could allow attackers to compromise user sessions or escalate privileges by injecting scripts that execute in the context of authenticated users. No known exploits are currently reported in the wild, and no official patches have been linked yet. However, the presence of this vulnerability necessitates prompt attention due to the potential for persistent client-side attacks and the sensitive nature of authentication plugins.

For European organizations, the impact of CVE-2025-58648 can be significant, especially for those relying on the Simple JWT Login plugin for authentication in their web applications. Exploitation could lead to unauthorized access to user accounts, data leakage, and potential lateral movement within internal networks if attackers leverage stolen credentials or session tokens. This could affect confidentiality by exposing sensitive user data, integrity by allowing unauthorized actions or data manipulation, and availability if attackers disrupt authentication flows. Organizations in sectors such as finance, healthcare, e-commerce, and government are particularly at risk due to the sensitive nature of data handled and regulatory requirements like GDPR. The cross-site scripting nature of the vulnerability also raises concerns about phishing and social engineering attacks, as malicious scripts could redirect users to fraudulent sites or capture input data. Given the medium severity and requirement for user interaction, the threat is moderate but can escalate if combined with other vulnerabilities or social engineering tactics. The absence of known exploits provides a window for mitigation before widespread attacks occur.

European organizations should implement the following specific mitigation measures: 1) Immediately audit all web applications using the Simple JWT Login plugin to identify affected versions (up to 3.6.4). 2) Apply any available patches or updates from the vendor as soon as they are released; if no official patch exists, consider temporary disabling or replacing the plugin. 3) Implement robust input validation and output encoding on all user-supplied data within the authentication workflows to prevent script injection. 4) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 5) Conduct regular security testing, including automated scanning and manual penetration testing focused on XSS vulnerabilities. 6) Educate users about the risks of clicking on suspicious links or interacting with unexpected prompts to reduce the likelihood of successful exploitation requiring user interaction. 7) Monitor web server and application logs for unusual activities that may indicate attempted exploitation. 8) Consider deploying Web Application Firewalls (WAFs) with rules targeting XSS attack patterns as an additional protective layer. These steps go beyond generic advice by focusing on the specific plugin and its role in authentication, emphasizing proactive detection and layered defenses.