CVE-2026-76265 in Splunk
Summary
by MITRE • 10/07/2026
In Splunk Enterprise versions below 10.4.3, 10.2.7, 10.0.10, and 9.4.15, and Splunk Secure Gateway versions below 3.10.11, 3.9.25, and 3.8.72, a user who does not hold the "admin" or "power" Splunk roles could access privileged Splunk Secure Gateway functionality. With this access, the user could cause Splunk Secure Gateway to sign attacker-controlled payloads. The vulnerability is possible because multiple Splunk Secure Gateway Representational State Transfer (REST) API endpoints do not enforce authorization requirements before processing requests.
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Analysis
by VulDB Data Team • 10/07/2026
The identified vulnerability in Splunk Enterprise and Splunk Secure Gateway represents a critical failure in access control mechanisms, specifically affecting versions prior to 10.4.3, 10.2.7, 10.0.10, and 9.4.15 for the enterprise platform, as well as versions below 3.10.11, 3.9.25, and 3.8.72 for Secure Gateway. This flaw allows unprivileged users who lack the admin or power roles to interact with sensitive administrative functions within Splunk Secure Gateway. The core technical deficiency lies in the improper implementation of authorization checks on multiple Representational State Transfer REST API endpoints. These endpoints fail to verify whether the requesting user possesses sufficient privileges before processing incoming requests, thereby bypassing the intended security boundaries established by the application's role-based access control model.
From a technical perspective, this vulnerability is classified under CWE-269, which denotes Improper Privilege Management. The absence of strict authorization enforcement at the API layer means that any authenticated user can invoke endpoints designed exclusively for high-level administrators. This architectural oversight enables an attacker to exploit these unprotected interfaces to perform actions typically reserved for system operators with elevated trust levels. In this specific instance, the exploitable functionality allows the manipulation of cryptographic signing processes within Splunk Secure Gateway. By leveraging the unrestricted API access, a malicious actor can force the gateway to sign payloads that are controlled by the attacker rather than legitimate administrative entities.
The operational impact of this vulnerability is severe due to its potential for supply chain compromise and integrity violations. When an attacker successfully causes Splunk Secure Gateway to sign their own crafted payloads, they effectively create trusted artifacts from a recognized security vendor's infrastructure. This capability undermines the trust model that relies on digital signatures to verify data authenticity and origin. Attackers can distribute these signed malicious payloads through legitimate channels, making them appear authentic to downstream systems or users who rely on signature verification for integrity assurance. Consequently, this flaw facilitates advanced persistent threats where malware or configuration changes are deployed with a veneer of legitimacy, potentially leading to unauthorized system modifications, data exfiltration, or further lateral movement within the network environment protected by Splunk Secure Gateway.
In terms of threat modeling and industry frameworks, this vulnerability aligns closely with MITRE ATT&CK technique T1556, which covers Modifying Authentication Process Mechanisms, as it involves altering how authentication tokens or signatures are generated for subsequent interactions. It also relates to T1078, Valid Accounts, because the exploitation relies on existing valid user credentials that lack appropriate role assignments but can still trigger privileged code paths due to the authorization bypass. The scenario exemplifies a classic privilege escalation via insecure direct object references or broken access control patterns where the system fails to distinguish between authorized and unauthorized actors for specific administrative operations.
To mitigate this risk, organizations must immediately upgrade Splunk Enterprise to version 10.4.3 or later, along with corresponding minor releases such as 10.2.7, 10.0.10, and 9.4.15. Similarly, users of Splunk Secure Gateway should update to version 3.10.11 or higher, including updates for the 3.9.x and 3.8.x branches up to their respective patch levels. Until patches are applied, administrators should implement strict network-level access controls to restrict API endpoint exposure only to known administrative IP addresses. Additionally, reviewing user role assignments is crucial; ensuring that no non-administrative users have unnecessary permissions can reduce the attack surface even if other vulnerabilities exist. Regular auditing of REST API logs for unusual activity patterns related to signing operations can also aid in early detection and response efforts.