CVE-2026-76337 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, an unauthenticated user could read JavaScript files outside the Splunk Web static directory. The vulnerability is possible because Splunk Web does not restrict static file requests to the configured static directory.
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Analysis
by VulDB Data Team • 08/20/2026
The identified vulnerability in Splunk Enterprise represents a critical path traversal and information disclosure flaw within the web server component, specifically affecting versions prior to 10.4.2, 10.2.6, 10.0.9, and 9.4.14. This security defect stems from an insufficient input validation mechanism in how Splunk Web handles requests for static files. Under normal operational parameters, web servers are configured with a designated document root or static directory to serve content such as HTML, CSS, JavaScript, and images. Access control mechanisms should strictly confine all file retrieval operations to this specific path hierarchy to prevent users from accessing sensitive system resources located elsewhere on the filesystem. In this instance, the application fails to enforce these boundaries, allowing an unauthenticated actor to manipulate request parameters to traverse directory structures upward using standard relative path notation.
From a technical perspective, the core flaw lies in the lack of canonicalization and boundary checks for file paths requested through the Splunk Web interface. When a user submits a URL pointing to a JavaScript resource, the backend processing logic does not adequately verify that the resolved absolute path remains within the intended static directory. By appending sequences such as dot-dot-slash or using encoded variants thereof, an attacker can escape the sandboxed web root and access arbitrary files on the underlying operating system. This behavior effectively bypasses authentication requirements because the vulnerability exists in the file serving infrastructure before any user identity verification is applied for these specific resource types. Consequently, sensitive configuration files, internal scripts containing hardcoded credentials or API keys, and other proprietary code can be read directly by an external party without needing valid login credentials.
The operational impact of this vulnerability is severe due to its unauthenticated nature and the sensitivity of the data potentially exposed. An attacker could harvest JavaScript source code that may contain logic for handling authentication tokens, session management, or integration with backend services. This information can be reverse-engineered to identify further attack vectors, such as crafting malicious payloads against other components or exploiting related vulnerabilities in the application logic. Furthermore, access to configuration files might reveal database connection strings, internal IP addresses, and service endpoints, facilitating more targeted attacks within the network perimeter. The ability to read arbitrary files also poses a risk of leaking environment variables or system-level secrets that are inadvertently stored in accessible locations, thereby compromising the confidentiality integrity of the entire Splunk deployment.
This vulnerability aligns with Common Weakness Enumeration category CWE-22: Improper Limitation of a Pathname to a Restricted Directory, which describes flaws where software does not properly neutralize special elements within a file path that can cause the path to resolve to a location outside of the restricted directory. Additionally, from an offensive security perspective, this flaw is consistent with ATT&CK technique T1083: File and Directory Discovery, as it enables an adversary to enumerate and access sensitive files on a compromised system without prior authentication. The lack of proper input sanitization allows for remote code execution prerequisites in some contexts if the retrieved data can be leveraged in subsequent injection attacks against other services.
To mitigate this risk, organizations running affected versions must immediately upgrade Splunk Enterprise to version 10.4.2 or later, where these path traversal restrictions have been enforced by default. For environments that cannot patch immediately due to compatibility constraints, network-level controls should be implemented to restrict access to the Splunk Web interface exclusively from trusted internal subnets using firewalls or reverse proxies with strict URL filtering capabilities. Administrators should also audit their deployment for any custom configurations that might override default security settings and ensure that sensitive files are not stored in directories accessible by the web server process. Regular vulnerability scanning and penetration testing focused on path traversal weaknesses are recommended to detect similar misconfigurations across other enterprise applications.