CVE-2025-36153 is a cross-site scripting (XSS) vulnerability classified under CWE-79, found in IBM Concert versions 1.0.0 through 2.0.0. This vulnerability arises from improper neutralization of input during web page generation, allowing an unauthenticated attacker to inject arbitrary JavaScript code into the web user interface. The injected script executes in the context of the victim's browser session, potentially altering the intended functionality of the application. This can lead to sensitive information disclosure, such as user credentials, session tokens, or other confidential data accessible within the trusted session. The vulnerability does not require authentication but does require user interaction, such as clicking a crafted link or visiting a malicious page that triggers the payload. The CVSS 3.1 base score is 6.1, reflecting a medium severity with network attack vector, low attack complexity, no privileges required, but requiring user interaction. The scope is changed (S:C), indicating that the vulnerability affects resources beyond the vulnerable component, potentially impacting the confidentiality and integrity of data. No patches or known exploits are currently available, but the vulnerability's presence in widely used IBM Concert versions makes it a significant risk. The lack of availability impact suggests the system remains operational but compromised in terms of data security.

For European organizations, this vulnerability poses a risk of credential theft and session hijacking, which can lead to unauthorized access to sensitive systems and data. Given IBM Concert's role in enterprise environments, exploitation could facilitate lateral movement within networks or unauthorized administrative actions. The confidentiality and integrity of user sessions are at risk, potentially exposing personal data and corporate secrets. This is especially critical for sectors with strict data protection regulations such as finance, healthcare, and government agencies in Europe. The vulnerability could also undermine trust in enterprise applications and lead to compliance violations under GDPR if personal data is compromised. Although no availability impact is noted, the indirect consequences of credential compromise could result in operational disruptions. The requirement for user interaction means phishing or social engineering campaigns could be used to exploit this vulnerability, increasing the threat surface for European entities with large user bases or remote workforce scenarios.

European organizations should implement multiple layers of defense to mitigate this vulnerability. Immediate steps include applying any available patches or updates from IBM once released. In the absence of patches, organizations should enforce strict input validation and output encoding on all user-supplied data within IBM Concert's web interface. Deploying Content Security Policy (CSP) headers can help restrict the execution of unauthorized scripts. Security teams should conduct thorough code reviews and penetration testing focused on XSS vectors in IBM Concert deployments. User education is critical to reduce the risk of successful social engineering attacks that could trigger exploitation. Network-level protections such as web application firewalls (WAFs) should be configured to detect and block malicious payloads targeting this vulnerability. Monitoring and logging user activity for unusual behavior can help detect exploitation attempts early. Finally, organizations should review and tighten session management controls to limit the impact of any credential disclosure.