CVE-2026-76256 in Splunk
Summary
by MITRE • 08/20/2026
In Splunk Enterprise versions below 10.4.2, 10.2.6, 10.0.9, and 9.4.14, and Splunk Secure Gateway versions below 3.10.9, 3.9.23, and 3.8.70, a user who does not hold the "admin" or "power" Splunk roles could read sensitive Security Assertion Markup Language setup and instance settings information through Splunk Secure Gateway Representational State Transfer (REST) API endpoints. The vulnerability is possible because the affected Security Assertion Markup Language setup and instance settings REST API endpoints do not enforce authorization requirements before returning configuration information.
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Analysis
by VulDB Data Team • 08/20/2026
The identified vulnerability in Splunk Enterprise versions prior to 10.4.2, 10.2.6, 10.0.9, and 9.4.14, as well as in Splunk Secure Gateway versions below 3.10.9, 3.9.23, and 3.8.70, represents a critical failure in access control mechanisms within the application's REST API layer. This flaw specifically affects endpoints responsible for managing Security Assertion Markup Language setup and instance settings configuration data. The core technical deficiency lies in the absence of proper authorization checks before these sensitive configuration details are returned to the requesting client. Consequently, any authenticated user possessing only minimal privileges, such as those lacking the admin or power roles, can successfully query these API endpoints to retrieve confidential system information that should be restricted to higher-privileged administrators.
From a technical perspective, this vulnerability is classified under CWE-269, which denotes Improper Privilege Control, and more specifically aligns with CWE-862 regarding Missing Authorization. The attack vector involves an unauthenticated or low-privilege actor sending HTTP requests directly to the affected REST API endpoints associated with SAML configuration retrieval. Because the server-side logic fails to verify whether the requesting user possesses sufficient permissions to view instance settings, it proceeds to serialize and transmit sensitive data including potentially internal network configurations, authentication provider details, and other security-critical parameters. This behavior violates the principle of least privilege by allowing users outside designated administrative groups to access resources that are intended for system management purposes only.
The operational impact of this vulnerability is significant as it facilitates an information disclosure attack that can serve as a precursor to more severe exploits. By exposing SAML setup details and instance settings, attackers gain insight into the authentication architecture and internal network topology of the Splunk deployment. This intelligence allows adversaries to map out trust relationships between identity providers and service providers within the organization's security infrastructure. Such exposure aids in crafting targeted phishing campaigns or configuring rogue identity providers for man-in-the-middle attacks against SAML assertions. Furthermore, knowledge of instance settings may reveal other misconfigurations or internal endpoints that could be leveraged for further lateral movement or privilege escalation attempts within the Splunk environment.
This vulnerability maps directly to several techniques within the MITRE ATT&CK framework, particularly T1087 which covers Account Discovery through local system queries and T1528 regarding Steal Application Access Token if tokens are exposed via these settings. The ability of low-privileged users to enumerate configuration data effectively allows them to understand the security controls in place without triggering high-severity alerts associated with administrative actions. This stealthy reconnaissance phase enables attackers to refine their attack strategies based on actual system configurations rather than assumptions, thereby increasing the likelihood of successful compromise and reducing detection probability during early stages of an intrusion campaign.
Mitigation for this vulnerability requires immediate patching of all affected Splunk Enterprise and Splunk Secure Gateway installations to the specified secure versions listed in the vendor advisory. Organizations should verify that their update processes include these specific version thresholds as minimum requirements for security compliance. In environments where immediate patching is not feasible, temporary mitigations may involve restricting network access to the REST API endpoints through firewall rules or reverse proxy configurations to ensure only authorized administrative workstations can reach them. Additionally, implementing strict input validation and enforcing role-based access control checks at the application layer before any configuration data is serialized for response transmission would address the root cause of this authorization bypass flaw until permanent fixes are deployed across all instances.