CVE-2025-36158 is a vulnerability identified in IBM Concert versions 1.0.0 through 2.0.0, classified under CWE-674, which relates to uncontrolled recursion. The flaw arises from the software's recursive directory copying mechanism that does not properly limit recursion depth or control the directory traversal process. This can be exploited by a local user who has specific permissions to trigger the uncontrolled recursion, potentially leading to the exposure of sensitive information contained within files. The vulnerability does not require user interaction and does not allow remote exploitation, as the attacker must have local access and the necessary permissions. The impact is primarily on confidentiality, as the attacker can read sensitive files they should not normally access. The CVSS v3.1 base score of 5.1 reflects a medium severity rating, with the vector indicating local attack vector (AV:L), high attack complexity (AC:H), no privileges required (PR:N), no user interaction (UI:N), unchanged scope (S:U), high confidentiality impact (C:H), no integrity impact (I:N), and no availability impact (A:N). Currently, there are no known exploits in the wild, and no official patches have been published by IBM, which increases the importance of interim mitigations. The vulnerability is particularly relevant for environments where IBM Concert is used for enterprise collaboration or document management, as sensitive data exposure could lead to compliance and privacy issues.

For European organizations, this vulnerability poses a risk of unauthorized local access to sensitive information, potentially including intellectual property, confidential business documents, or personal data protected under GDPR. The confidentiality breach could lead to regulatory penalties, reputational damage, and competitive disadvantage. Since exploitation requires local access and specific permissions, the threat is more significant in environments with many users or insufficient privilege separation. Organizations in sectors such as finance, manufacturing, and government, which often use IBM enterprise products, may face higher risks. The lack of integrity and availability impact limits the threat to data leakage rather than system disruption, but the exposure of sensitive data can still have severe consequences. The absence of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits once the vulnerability becomes widely known.

European organizations should immediately audit and restrict local user permissions on systems running IBM Concert to the minimum necessary, ensuring that only trusted users have the specific permissions required to trigger the vulnerability. Implement strict access controls and monitoring to detect unusual recursive directory operations or file access patterns. Employ host-based intrusion detection systems (HIDS) to alert on suspicious local activities. Segregate systems running IBM Concert from general user environments to limit local access. Regularly back up sensitive data and maintain an incident response plan tailored to data exposure scenarios. Engage with IBM support channels to obtain updates on patches or workarounds and apply them promptly once available. Additionally, conduct user training to raise awareness about the risks of local privilege misuse and enforce strong endpoint security policies to prevent unauthorized local access.