CVE-2025-71276 is a Cross-site Scripting (XSS) vulnerability classified under CWE-79 that affects Alinto's SOGo groupware software versions prior to 5.12.5. The vulnerability stems from improper neutralization of user-supplied input during web page generation within the events, tasks, and contacts categories. This flaw allows an authenticated user with low privileges to inject malicious scripts into the web interface, which are then executed in the context of other users' browsers without requiring any user interaction. The vulnerability has a CVSS 3.1 base score of 6.4, indicating medium severity, with an attack vector of network, low attack complexity, requiring privileges, no user interaction, and a scope change. The impact affects confidentiality and integrity partially, but not availability. The vulnerability could be exploited to steal session tokens, perform unauthorized actions, or manipulate displayed data, potentially leading to further compromise within affected environments. No public exploits have been reported yet, but the vulnerability is publicly disclosed and should be addressed promptly. The lack of a patch link suggests that users should monitor vendor advisories for updates or apply workarounds such as input sanitization and output encoding to mitigate risk.

The vulnerability allows attackers with low-level authenticated access to inject malicious scripts that execute in other users' browsers, potentially leading to theft of session cookies, unauthorized actions, or data manipulation. This compromises the confidentiality and integrity of user data within the SOGo environment. While availability is not affected, the breach of trust and data integrity can disrupt organizational workflows and lead to further exploitation, such as privilege escalation or lateral movement. Organizations relying on SOGo for email, calendar, and contact management face risks of internal data leakage and user impersonation. The medium severity rating reflects the requirement for authentication and the absence of user interaction, limiting the attack surface but still posing a significant threat in environments with multiple users and shared access.

Organizations should upgrade SOGo to version 5.12.5 or later once available to fully remediate this vulnerability. Until patches are released, implement strict input validation and output encoding on all user-supplied data in events, tasks, and contacts categories to prevent script injection. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in the web interface. Limit user privileges to the minimum necessary to reduce the risk of exploitation. Monitor logs for unusual activity related to event, task, or contact modifications. Educate users about the risks of XSS and encourage cautious behavior when interacting with shared content. Regularly review and update web application firewalls (WAFs) to detect and block XSS attack patterns targeting SOGo. Coordinate with the vendor for timely updates and advisories.