CVE-2025-2786 is a vulnerability identified in the Tempo Operator, a Kubernetes operator used to deploy TempoStack or TempoMonolithic instances. When a user deploys these instances, the operator automatically creates a ServiceAccount, ClusterRole, and ClusterRoleBinding. The flaw lies in the fact that a user with full access to their own namespace can extract the ServiceAccount token associated with these resources. This token can then be used to submit TokenReview and SubjectAccessReview API requests to the Kubernetes API server. These requests allow the user to query the permissions and roles assigned to other users or service accounts within the cluster, effectively exposing sensitive authorization information. Importantly, this vulnerability does not permit privilege escalation or impersonation of other users; it solely leaks information about user permissions. The CVSS v3.1 base score is 4.3 (medium severity), reflecting the network attack vector, low complexity, and requirement for privileges at the namespace level. The vulnerability does not require user interaction and affects the confidentiality of authorization data but does not impact integrity or availability. No patches or exploits are currently reported, but the information disclosure could facilitate reconnaissance for more targeted attacks in Kubernetes environments using Tempo Operator.

For European organizations, the exposure of sensitive authorization information can undermine the security posture of Kubernetes clusters running Tempo Operator. Attackers or malicious insiders with namespace-level access could leverage this information to map out user permissions and roles, aiding in the planning of privilege escalation or lateral movement attacks. This is particularly concerning for organizations with multi-tenant Kubernetes clusters or those that rely heavily on RBAC for access control. The leak of permission data could also violate data protection regulations if it leads to unauthorized access or data breaches. While the vulnerability does not directly allow privilege escalation, the reconnaissance advantage it provides could increase the risk of subsequent, more damaging attacks. Organizations in sectors with stringent compliance requirements, such as finance, healthcare, and critical infrastructure, may face increased risk and regulatory scrutiny if such vulnerabilities are exploited.

To mitigate CVE-2025-2786, organizations should: 1) Restrict namespace-level privileges strictly to trusted users and service accounts, minimizing who can deploy TempoStack or TempoMonolithic instances. 2) Implement strict RBAC policies that limit the ability to extract ServiceAccount tokens or perform TokenReview and SubjectAccessReview requests. 3) Monitor Kubernetes audit logs for unusual TokenReview or SubjectAccessReview API calls that could indicate reconnaissance activity. 4) Use Kubernetes features such as Bound ServiceAccount Tokens or TokenRequest API with limited scopes to reduce token misuse. 5) Keep Tempo Operator and related components updated; although no patch links are currently provided, monitor vendor advisories for fixes. 6) Consider network segmentation and API server access controls to limit exposure of sensitive API endpoints. 7) Conduct regular security assessments and penetration tests focusing on Kubernetes RBAC configurations and operator deployments to detect similar information disclosure risks.