CVE-2026-76268 in Splunk
Summary
by MITRE • 10/07/2026
In Splunk Enterprise versions below 10.4.3 and 10.2.7, an unauthenticated user with network access to the Patroni Representational State Transfer (REST) Application Programming Interface (API) on a search head cluster member could execute attacker-controlled operating-system commands. The vulnerability is possible because this interface does not require authentication for critical configuration operations. For more information see Sidecar configuration settings (https://help.splunk.com/en/data-management/splunk-enterprise-admin-manual/10.2/splunk-sidecars/sidecar-configuration-settings) in the Splunk documentation.
Splunk Enterprise versions 10.0.x and 9.4.x are not affected.
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Analysis
by VulDB Data Team • 10/07/2026
A critical security vulnerability has been identified within specific early releases of Splunk Enterprise, specifically affecting version 10.3.x prior to patch level 10.4.3 and the long-term support release branch 10.2.x prior to patch level 10.2.7. This flaw resides in the Patroni Representational State Transfer application programming interface deployed on search head cluster members, which serves as a mechanism for managing database configuration settings within the Splunk infrastructure. The core technical deficiency is an absence of authentication enforcement for critical configuration operations exposed through this API endpoint. Consequently, any actor possessing network-level connectivity to the affected service can interact with these endpoints without providing valid credentials or session tokens. This lack of access control allows an unauthenticated remote attacker to inject malicious payloads into the system configuration parameters that are subsequently processed by underlying operational components.
The exploitation vector for this vulnerability centers on the ability to manipulate sidecar configurations, which are integral to how Splunk manages external processes and data collection agents. By leveraging the unprotected REST API endpoints associated with Patroni, an adversary can execute attacker-controlled operating-system commands directly on the host machine running the search head cluster member. This capability effectively bypasses all intended security boundaries of the application layer, granting the threat actor a foothold equivalent to that of a local user with elevated privileges within the context of the Splunk service account. The impact is severe, as it enables full system compromise, allowing for data exfiltration, lateral movement across the cluster, and potential persistence mechanisms being established on the affected infrastructure components.
From an industry standard perspective, this vulnerability aligns closely with CWE-287, which describes Improper Authentication, where a software product does not correctly verify that an actor is authorized to perform an action before executing it. Furthermore, in terms of tactical mapping within the MITRE ATT&CK framework, this flaw facilitates Initial Access and Command and Control activities by allowing remote code execution through legitimate administrative interfaces that have been left improperly secured. The vulnerability highlights a common architectural risk where internal management APIs are exposed without sufficient zero-trust verification mechanisms, particularly when these interfaces handle sensitive configuration data that directly influences system behavior at the operating system level.
Splunk Enterprise versions 10.0.x and 9.4.x are not affected by this specific issue, indicating that the regression or introduction of this flaw occurred in later development cycles leading up to version 10.3.x. Organizations running impacted versions must prioritize immediate remediation efforts. The primary mitigation strategy is to upgrade Splunk Enterprise to version 10.2.7 or higher for the 10.2 branch, and version 10.4.3 or higher for the 10.3 branch, where authentication requirements have been enforced on these critical API endpoints. In environments where immediate patching is not feasible due to operational constraints, network segmentation strategies should be implemented to restrict access to the Patroni REST API exclusively from trusted management subnets with strict firewall rules denying all unauthenticated traffic. Additionally, monitoring for anomalous configuration changes or unexpected process executions originating from search head cluster members can aid in detecting potential exploitation attempts during the remediation window.