CVE-2026-76316 in Splunk
Summary
by MITRE • 08/20/2026
In Splunk Enterprise versions below 10.4.1, 10.2.5, 10.0.9, and 9.4.14, an unauthenticated user who can reach the Splunk management port could store a Search Processing Language (SPL) pipeline that runs when an administrator opens the Add Data forwarder workflow. The SPL pipeline could access all relevant data, affect system integrity, and affect availability of the Splunk platform instance. The SPL injection is possible because Deployment Server client identifiers are placed into dispatched searches without neutralizing special characters. Successful exploitation requires an administrator to open the affected Add Data forwarder workflow after the unauthenticated user registers a crafted Deployment Server client identity. For more information see Forward data (https://help.splunk.com/en/splunk-enterprise/get-started/get-data-in/10.2/how-to-get-data-into-your-splunk-deployment/forward-data) and About agent management (https://help.splunk.com/en/splunk-enterprise/administer/update-your-deployment/10.4/agent-management/about-agent-management) in the Splunk documentation.
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Analysis
by VulDB Data Team • 08/20/2026
The vulnerability identified in specific versions of Splunk Enterprise, including releases prior to 10.4.1, 10.2.5, 10.0.9, and 9.4.14, represents a critical security flaw rooted in improper input validation within the deployment management subsystem. This issue allows an unauthenticated attacker who has network access to the Splunk management port to inject malicious Search Processing Language (SPL) code into the system. The core technical failure lies in how Deployment Server client identifiers are handled during the creation of dispatched searches. Specifically, these identifiers are inserted directly into search queries without adequate sanitization or neutralization of special characters that hold syntactic meaning within SPL. This lack of proper encoding creates a classic injection vector where user-supplied data is interpreted as executable code rather than literal string data.
The operational impact of this vulnerability is severe due to the context in which the injected payload executes. The malicious SPL pipeline does not run immediately upon registration by an unauthenticated user; instead, it remains dormant until triggered by a privileged action. Specifically, when a Splunk administrator opens the Add Data forwarder workflow, the system processes the previously registered client identifiers as part of the search dispatch process. At this moment, the injected code is executed with the privileges associated with that administrative context. This design flaw effectively bridges the gap between unauthenticated network access and authenticated privilege escalation, allowing an external attacker to achieve remote code execution capabilities within the Splunk environment without prior authentication credentials for a user account.
The consequences of successful exploitation are multifaceted and potentially devastating to the integrity and availability of the Splunk platform instance. Because SPL is designed to query and manipulate data stored within the Splunk index, the injected pipeline can access all relevant data indexed by the system. This includes sensitive logs, security events, application metrics, and other confidential information that organizations rely on for monitoring and compliance. Beyond confidentiality breaches, an attacker with control over search execution can alter or delete critical configurations, corrupt indexes, or generate resource-intensive searches designed to exhaust CPU and memory resources. Such actions directly compromise the availability of the Splunk service, potentially causing denial-of-service conditions that disrupt security operations centers and incident response capabilities.
This vulnerability aligns closely with Common Weakness Enumeration (CWE) categories such as CWE-94 Improper Control of Generation of Code or Script Injection and CWE-78 Improper Neutralization of Special Elements used in an OS Command, specifically within the context of application-level command injection via SPL syntax. From a threat modeling perspective consistent with the MITRE ATT&CK framework, this exploit path resembles techniques associated with Initial Access through trusted infrastructure components and Execution via scheduled tasks or administrative workflows. The reliance on an administrator's action to trigger the payload classifies it as a time-of-check-to-time-of-use (TOCTOU) variant where trust in the deployment server identity is abused without sufficient validation of the data structure itself.
Mitigation strategies must prioritize immediate patching and access control adjustments. Organizations running affected versions should upgrade Splunk Enterprise to version 10.4.1, 10.2.5, 10.0.9, or 9.4.14 or later as soon as possible, as these releases contain the necessary fixes for input sanitization in the deployment server client identifier handling. In environments where immediate patching is not feasible due to operational constraints, network segmentation should be enforced to restrict access to the Splunk management port exclusively from trusted internal subnets and administrative workstations. Additionally, implementing strict firewall rules that limit exposure of the management interface to only necessary IP addresses can significantly reduce the attack surface for unauthenticated actors attempting to register malicious deployment clients. Regular auditing of deployed forwarders and monitoring for unusual search activity patterns can also aid in early detection of exploitation attempts before significant damage occurs.