CVE-2025-20366 is a vulnerability affecting Splunk Enterprise versions below 9.4.4, 9.3.6, and 9.2.8, as well as corresponding versions of Splunk Cloud Platform. The issue arises because Splunk does not adequately restrict access to search job results when those jobs are run with administrative privileges in the background. Specifically, a low-privileged user who does not have admin or power roles can access sensitive search results if they correctly guess the unique Search ID (SID) associated with an administrative search job. The SID acts as a key to retrieve the job’s results, and if exposed, it can leak sensitive data contained in those search results. This vulnerability is exploitable remotely without user interaction, requiring only low privileges and knowledge or guessing of the SID. The CVSS v3.1 score is 6.5, reflecting a medium severity with high confidentiality impact but no impact on integrity or availability. The vulnerability is rooted in improper access control mechanisms around job management and search result retrieval in Splunk’s architecture. No public exploits have been reported yet, but the potential for sensitive data exposure is significant, especially in environments where Splunk is used to analyze security logs, network traffic, or other confidential information. The vulnerability affects multiple recent versions of Splunk Enterprise and Cloud Platform, necessitating prompt patching or mitigation by affected organizations.

For European organizations, the primary impact of CVE-2025-20366 is the unauthorized disclosure of sensitive information contained in Splunk search results. Since Splunk is widely used for security monitoring, log analysis, and operational intelligence, exposure of these results could reveal confidential operational data, security alerts, or personally identifiable information (PII). This could lead to compliance violations under GDPR and other data protection regulations, reputational damage, and increased risk of targeted attacks if threat intelligence or internal security posture details are leaked. The vulnerability does not allow modification or disruption of services, so integrity and availability impacts are minimal. However, the confidentiality breach alone can have serious consequences in sectors such as finance, telecommunications, government, and critical infrastructure, where Splunk is heavily deployed. The ease of exploitation (low privilege and no user interaction) increases the risk profile, especially in multi-tenant or shared environments where low-privileged users exist. Organizations that have not upgraded to patched versions remain vulnerable to potential insider threats or attackers who gain low-level access.

To mitigate CVE-2025-20366, European organizations should immediately upgrade affected Splunk Enterprise and Splunk Cloud Platform instances to versions 9.4.4, 9.3.6, 9.2.8 or later, as these contain the necessary access control fixes. Until upgrades can be applied, organizations should restrict access to the Splunk search job management interfaces and ensure that low-privileged users cannot enumerate or guess Search IDs (SIDs). Implement network segmentation and strict role-based access controls (RBAC) to limit which users can view or interact with search jobs. Monitoring and alerting on unusual access patterns to search job endpoints can help detect exploitation attempts. Additionally, review and audit Splunk user roles and permissions regularly to minimize the number of users with elevated privileges. If possible, disable or limit background administrative search jobs that produce sensitive results accessible via SIDs. Finally, educate administrators and security teams about this vulnerability and the importance of applying patches promptly.