CVE-2025-36326 is a vulnerability identified in IBM Cognos Controller versions 11.0.0 through 11.0.1 and 11.1.0 through 11.1.1. The issue stems from the use of hard-coded cryptographic keys employed to sign session cookies. Hard-coded keys are embedded directly into the application code or configuration and do not change per deployment or user session, which significantly weakens the cryptographic protection of sensitive data. In this case, the session cookies, which are critical for maintaining authenticated user sessions, are signed using a static key. An attacker who discovers or extracts this key can potentially forge or tamper with session cookies, leading to unauthorized access or information disclosure. The vulnerability is classified under CWE-321 (Use of Hard-coded Cryptographic Key), which is a recognized weakness that undermines cryptographic security. The CVSS v3.1 base score is 3.7, indicating a low severity primarily because the attack vector is network-based but requires high attack complexity, no privileges, and no user interaction. The impact is limited to confidentiality, with no direct impact on integrity or availability. No known exploits are currently reported in the wild, and no patches have been published at the time of this report. The vulnerability affects IBM Cognos Controller, a financial performance management software widely used for consolidations, reporting, and analysis in enterprise environments. The presence of hard-coded keys in session cookie signing can allow attackers to obtain sensitive information by forging or decrypting session tokens, potentially leading to unauthorized data access within affected deployments.

For European organizations using IBM Cognos Controller, this vulnerability poses a risk to the confidentiality of session data. Attackers exploiting this flaw could impersonate legitimate users or access sensitive financial and operational data managed within the Cognos Controller environment. While the vulnerability does not directly affect system integrity or availability, unauthorized access to session information can lead to data leakage, compliance violations (e.g., GDPR), and erosion of trust in financial reporting processes. Given the critical nature of financial data in European enterprises, especially in regulated sectors such as banking, insurance, and public administration, even low-severity vulnerabilities can have outsized reputational and regulatory consequences. The lack of known exploits reduces immediate risk, but the static nature of the cryptographic key means that once discovered, the vulnerability could be exploited repeatedly. Organizations relying on IBM Cognos Controller should consider this a potential vector for insider threats or external attackers who gain network access. The impact is heightened in environments where session cookies are transmitted over insecure channels or where additional compensating controls are absent.

To mitigate this vulnerability, European organizations should: 1) Monitor IBM's official channels for patches or updates addressing CVE-2025-36326 and apply them promptly once available. 2) In the interim, restrict network access to IBM Cognos Controller interfaces to trusted internal networks and enforce strong network segmentation to limit exposure. 3) Implement additional session management controls such as enforcing HTTPS/TLS for all communications to protect session cookies in transit. 4) Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block anomalous session cookie usage or replay attempts. 5) Conduct regular security audits and code reviews to identify any other hard-coded secrets or cryptographic weaknesses. 6) Educate administrators and users about the risks of session hijacking and enforce multi-factor authentication (MFA) where possible to reduce the impact of compromised sessions. 7) Review and enhance logging and monitoring to detect suspicious session activity promptly. These steps go beyond generic advice by focusing on compensating controls and proactive detection until an official patch is released.