CVE-2025-36005 is a medium-severity vulnerability affecting multiple versions of the IBM MQ Operator, specifically versions ranging from 2.0.0 LTS through 2.0.29, various CD and SC2 releases up to 3.6.0. The vulnerability stems from improper certificate validation (CWE-295) in the Internet Pass-Thru component of the MQ Operator. This flaw allows a malicious actor to potentially intercept and obtain sensitive information from another TLS session connection proxied to the same hostname and port. Essentially, the MQ Operator fails to correctly validate TLS certificates, which undermines the security guarantees of TLS sessions. This can lead to information disclosure without requiring authentication or user interaction. The CVSS v3.1 base score is 5.9, reflecting a medium severity level, with a vector indicating network attack vector, high attack complexity, no privileges required, no user interaction, unchanged scope, high confidentiality impact, and no integrity or availability impact. There are no known exploits in the wild as of the publication date (July 24, 2025), and no patches have been linked yet. The vulnerability affects the confidentiality of data transmitted over TLS connections managed by the IBM MQ Operator, which is widely used for enterprise messaging and integration in hybrid cloud environments.

For European organizations, the impact of CVE-2025-36005 can be significant, especially for those relying on IBM MQ Operator for secure message queuing and integration across cloud and on-premises environments. The improper certificate validation could allow attackers to intercept sensitive data such as credentials, business-critical messages, or personally identifiable information (PII) transmitted over TLS sessions. This undermines data confidentiality and could lead to compliance violations under GDPR and other data protection regulations. Since IBM MQ is often used in financial services, manufacturing, and government sectors—industries prevalent across Europe—the risk of sensitive data leakage is heightened. The medium severity rating suggests that while exploitation requires high attack complexity, the lack of required privileges or user interaction means attackers could potentially exploit this remotely if they can position themselves on the network path. This could facilitate espionage, data theft, or further lateral movement within affected networks. The absence of known exploits currently provides a window for mitigation, but organizations should act proactively given the strategic importance of IBM MQ in critical infrastructure and enterprise systems.

1. Immediate mitigation should include reviewing network segmentation and access controls to limit exposure of IBM MQ Operator endpoints to untrusted networks. 2. Monitor network traffic for unusual TLS session behaviors or proxy anomalies that could indicate exploitation attempts. 3. Implement strict TLS certificate management policies, including certificate pinning where feasible, to reduce reliance on potentially flawed validation mechanisms. 4. Engage with IBM support channels to obtain patches or workarounds as soon as they become available, and prioritize timely deployment. 5. Conduct thorough security assessments and penetration testing focused on TLS session handling within IBM MQ Operator deployments. 6. Use additional encryption layers or VPN tunnels to protect sensitive message traffic beyond TLS. 7. Maintain up-to-date inventory of affected IBM MQ Operator versions and plan for upgrades to versions not impacted by this vulnerability. 8. Educate security teams about this vulnerability to enhance detection and incident response capabilities.