CVE-2025-58626 is a Stored Cross-site Scripting (XSS) vulnerability affecting RumbleTalk Live Group Chat versions up to 6.3.5. This vulnerability arises from improper neutralization of input during web page generation, classified under CWE-79. Specifically, user-supplied input is not adequately sanitized or encoded before being embedded into the web pages generated by the chat application. As a result, an attacker can inject malicious scripts that are stored persistently on the server and executed in the browsers of users who access the affected chat pages. The vulnerability has a CVSS 3.1 base score of 6.5, indicating a medium severity level. The vector string (AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L) shows that the attack can be launched remotely over the network with low attack complexity, requires low privileges, and user interaction is needed to trigger the malicious script. The scope is changed, meaning the vulnerability affects components beyond the initially vulnerable component. The impact affects confidentiality, integrity, and availability to a limited extent. Although no known exploits are currently reported in the wild, the stored nature of the XSS makes it particularly dangerous as it can affect multiple users over time once the malicious payload is stored. RumbleTalk Live Group Chat is a web-based group chat solution often embedded in websites for real-time communication, making this vulnerability a concern for organizations relying on it for customer or internal communications. Attackers exploiting this flaw could steal session cookies, perform actions on behalf of users, or deliver further malware payloads through the injected scripts.

For European organizations using RumbleTalk Live Group Chat, this vulnerability poses a risk to user data confidentiality and the integrity of communications. Attackers could hijack user sessions, leading to unauthorized access to sensitive chat content or user accounts. The availability of the chat service could also be impacted if attackers inject scripts that disrupt normal operations or cause denial of service. Given the collaborative nature of group chats, exploitation could facilitate lateral movement or social engineering attacks within organizations. This is particularly critical for sectors such as finance, healthcare, and government agencies in Europe, where sensitive information is frequently exchanged. Additionally, exploitation could lead to reputational damage and regulatory consequences under GDPR if personal data is compromised. The requirement for low privileges and remote exploitation increases the threat surface, especially in environments where chat users have elevated roles or access rights.

Organizations should immediately verify if their RumbleTalk Live Group Chat deployment is running a vulnerable version (up to 6.3.5) and plan to upgrade to a patched version once available. In the absence of an official patch, temporary mitigations include implementing strict Content Security Policy (CSP) headers to restrict script execution and reduce the impact of injected scripts. Input validation and output encoding should be enforced at the application layer to sanitize user inputs before rendering. Web application firewalls (WAFs) can be configured to detect and block common XSS payloads targeting the chat application. Monitoring chat logs for suspicious input patterns and educating users about the risks of clicking unknown links or executing unexpected scripts can further reduce risk. Finally, organizations should conduct regular security assessments and penetration tests focusing on chat interfaces to identify and remediate similar vulnerabilities proactively.