CVE-2025-28929 identifies a stored Cross-site Scripting (XSS) vulnerability in the Vivek Marakana Tabbed Login Widget, specifically versions up to and including 1.1.2. The root cause is improper neutralization of user-supplied input during the generation of web pages, which allows attackers to inject malicious JavaScript code that is stored persistently within the application. When other users access the affected pages, the malicious script executes in their browsers under the context of the vulnerable site. This can lead to theft of session cookies, redirection to malicious sites, or execution of unauthorized actions on behalf of the victim. The vulnerability does not require authentication or user interaction beyond visiting the compromised page, increasing its risk profile. Although no public exploits have been reported yet, the nature of stored XSS makes it a critical concern for web applications relying on this widget. The vulnerability affects the Tabbed Login Widget, a component used to manage user authentication interfaces, which may be embedded in various websites and web applications. No official patches or updates are currently linked, so mitigation relies on best practices such as input validation, output encoding, and deployment of Content Security Policies. The vulnerability was published on March 11, 2025, and is tracked by Patchstack, but lacks a CVSS score, necessitating an independent severity assessment.

The primary impact of this vulnerability is on the confidentiality and integrity of user data and sessions. Stored XSS allows attackers to execute arbitrary scripts in the context of the vulnerable website, potentially leading to session hijacking, theft of sensitive information such as credentials or personal data, and unauthorized actions performed on behalf of legitimate users. This can result in account compromise, data breaches, and erosion of user trust. Additionally, attackers may use the vulnerability to deliver malware or conduct phishing attacks by manipulating the website content. The availability impact is generally low unless combined with other vulnerabilities or used in a broader attack chain. Organizations running websites with the affected Tabbed Login Widget risk reputational damage and regulatory penalties if user data is compromised. The lack of authentication requirement and ease of exploitation increase the threat level, especially for high-traffic websites or those with sensitive user bases.

1. Monitor for official patches or updates from the Vivek Marakana project and apply them promptly once available. 2. Implement strict input validation on all user-supplied data fields to reject or sanitize potentially malicious content before storage or rendering. 3. Employ robust output encoding (e.g., HTML entity encoding) when displaying user input to prevent script execution. 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 code reviews and penetration testing focused on input handling and output generation in the login widget and related components. 6. Consider isolating or replacing the vulnerable widget with alternative, well-maintained authentication components that follow secure coding practices. 7. Educate developers and administrators about XSS risks and secure coding standards to prevent similar vulnerabilities in the future. 8. Monitor web application logs and user reports for suspicious activities that may indicate exploitation attempts.