CVE-2026-25958 is a vulnerability classified under CWE-807 (Reliance on Untrusted Inputs in a Security Decision) affecting the cube-js cube semantic layer, a tool used to build data applications. The issue exists in versions from 0.27.19 up to but not including 1.0.14, 1.1.0 up to 1.4.2, and 1.5.0 up to 1.5.13. The vulnerability allows an attacker who possesses a valid API token but has limited privileges to craft special requests that escalate their privileges within the system. This escalation occurs because the cube-js software improperly trusts inputs used in security decisions, failing to adequately validate or sanitize them, thereby allowing unauthorized privilege elevation. The CVSS v3.1 score of 7.7 reflects a high severity, with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), no user interaction (UI:N), and a scope change (S:C). The impact is primarily on confidentiality (C:H), with no direct impact on integrity or availability. The vulnerability was published on February 9, 2026, and fixed in versions 1.5.13, 1.4.2, and 1.0.14. No public exploits have been reported yet, but the nature of the flaw suggests that attackers with some level of access could leverage it to gain unauthorized data access or control within affected systems.

For European organizations, the impact of CVE-2026-25958 is significant, especially for those relying on cube-js for their data application layers. The privilege escalation can lead to unauthorized access to sensitive data, potentially violating GDPR and other data protection regulations. Confidentiality breaches could result in data leaks, intellectual property theft, or exposure of personal data. Since the vulnerability does not affect integrity or availability directly, the primary concern is unauthorized data disclosure and lateral movement within networks. Organizations in sectors such as finance, healthcare, and government, which handle sensitive or regulated data, are particularly at risk. The exploitation requires a valid API token with some privileges, which means insider threats or compromised credentials could be leveraged. The lack of required user interaction makes automated or remote exploitation feasible, increasing the threat level. The absence of known exploits in the wild currently reduces immediate risk but does not eliminate the potential for future attacks.

To mitigate CVE-2026-25958, European organizations should promptly upgrade cube-js to versions 1.5.13, 1.4.2, or 1.0.14 or later, where the vulnerability is patched. Additionally, organizations should audit API token issuance and usage policies to ensure tokens are granted with the least privilege necessary and are rotated regularly. Implement strict monitoring and logging of API requests to detect anomalous or suspicious activity indicative of privilege escalation attempts. Employ network segmentation and access controls to limit the impact of compromised tokens. Conduct regular security assessments and penetration testing focused on API security and privilege management. Educate developers and administrators about secure coding practices related to input validation and security decision logic. Finally, consider implementing multi-factor authentication and anomaly detection on API access to reduce the risk of token misuse.