CVE-2025-36161 identifies a vulnerability in IBM Concert versions 1.0.0 through 2.0.0 related to improper enforcement of HTTP Strict-Transport-Security (HSTS). HSTS is a web security policy mechanism that helps protect websites against protocol downgrade attacks and cookie hijacking by instructing browsers to interact with the server only over HTTPS. The failure to enable HSTS properly means that the application may accept HTTP connections or fail to enforce HTTPS strictly, exposing communications to interception. This vulnerability is categorized under CWE-327, indicating the use of a broken or risky cryptographic algorithm or mechanism. In this case, the risk arises from the lack of strict transport security rather than a cryptographic algorithm flaw per se, but it results in similar confidentiality risks. An attacker positioned on the network path can exploit this by performing man-in-the-middle attacks, intercepting or modifying sensitive data transmitted between clients and the IBM Concert server. The CVSS v3.1 score is 5.9 (medium), reflecting network attack vector, high attack complexity, no privileges required, no user interaction, and high confidentiality impact but no integrity or availability impact. No patches or exploits are currently documented, but the vulnerability poses a significant risk to data confidentiality if exploited.

For European organizations, the primary impact is the potential exposure of sensitive information transmitted via IBM Concert due to MitM attacks exploiting the lack of HSTS enforcement. This could lead to unauthorized disclosure of confidential business data, intellectual property, or personal data, potentially violating GDPR and other data protection regulations. The vulnerability does not affect data integrity or availability directly but undermines trust in secure communications. Organizations in sectors such as finance, healthcare, government, and critical infrastructure that rely on IBM Concert for collaboration or data exchange are particularly at risk. The medium severity rating suggests that while exploitation is not trivial, the consequences of successful attacks could be significant, especially in environments with high-value data. The absence of known exploits in the wild provides a window for proactive mitigation before attackers develop weaponized methods.

Organizations should immediately verify whether IBM Concert versions 1.0.0 through 2.0.0 are deployed in their environments. Since no official patches are currently available, administrators must manually enforce HTTPS by configuring web servers and application gateways to redirect all HTTP traffic to HTTPS and enable HSTS headers with appropriate parameters (e.g., 'max-age', 'includeSubDomains', 'preload'). Network-level protections such as TLS interception detection, strict certificate validation, and use of VPNs can reduce MitM risks. Regular network traffic monitoring and anomaly detection should be implemented to identify suspicious interception attempts. Additionally, organizations should engage with IBM support for updates or patches and plan for timely upgrades to fixed versions once released. Employee awareness about secure access and reporting unusual connection warnings in browsers can further reduce risk.