CVE-2026-78599 in Kibana
Summary
by MITRE • 09/02/2026
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') (CWE-22) in the Kibana Fleet feature can lead to the unauthorized deletion of internal resources via Path Traversal (CAPEC-126). A low-privileged user holding Fleet write access could cause a subsequent administrative delete action to act on unintended internal resources. Exploitation requires an administrator to interact with the affected Fleet interface.
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Analysis
by VulDB Data Team • 09/02/2026
The vulnerability identified as CWE-22, commonly known as Path Traversal or Directory Traversal, represents a critical security flaw within the Kibana Fleet feature of Elastic Stack environments. This specific implementation error stems from insufficient validation and sanitization of user-supplied input when constructing file system paths for internal operations. In this context, the application fails to properly restrict pathname resolution to a designated safe directory, allowing an attacker to manipulate path sequences such as dot-dot-slash (../) or other platform-specific variations to escape the intended scope. This lack of strict boundary enforcement enables the traversal outside of restricted directories where sensitive configuration files, internal state data, and critical system resources are stored. The root cause lies in the failure to canonicalize paths before performing access control checks, a fundamental oversight that permits relative path manipulation to target arbitrary locations on the underlying operating system file structure.
The operational impact of this vulnerability is severe due to its potential for unauthorized deletion of internal resources. A low-privileged user who possesses write access to the Fleet feature can craft malicious requests designed to exploit this pathname limitation. By injecting traversal sequences into input fields, such as agent configuration parameters or package installation paths, the attacker can redirect administrative delete actions toward unintended targets. This effectively allows a lower-level actor to influence high-privilege operations by tricking an administrator interface into executing destructive commands on critical system files. The consequence is not merely data exposure but potential denial of service through resource destruction, which can disrupt fleet management capabilities and compromise the integrity of the entire Elastic Stack deployment if core configuration or log storage directories are affected.
From a threat modeling perspective, this vulnerability aligns with CAPEC-126, Path Traversal, where an attacker leverages insufficient input validation to access restricted areas of a system. The attack vector is classified as remote but requires user interaction, specifically that an administrator must interact with the affected Fleet interface after the malicious payload has been submitted by the low-privileged user. This social engineering or privilege escalation aspect means that while the initial exploit code can be executed by a lower-level account, successful exploitation depends on administrative oversight of the compromised input. The ATT&CK framework categorizes this under techniques related to Command and Scripting Interpreter abuse or File System Discovery depending on the specific outcome, but primarily it falls under Privilege Escalation via manipulation of trusted processes if the delete action triggers further system changes.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary defense is ensuring that all pathname inputs are strictly validated against a whitelist of allowed characters and paths before being processed by file system operations. Implementing canonicalization checks to resolve symbolic links and relative path components early in the request lifecycle can prevent traversal attempts from succeeding. Additionally, applying the principle of least privilege ensures that low-privileged users have minimal write access within the Fleet feature, reducing the attack surface for such manipulations. Regular security audits and static code analysis focused on CWE-22 patterns are essential to identify similar flaws across other modules. Organizations should also enforce multi-factor authentication and strict role-based access controls to minimize the risk of an administrator inadvertently interacting with maliciously crafted inputs submitted by lower-level accounts, thereby breaking the chain of exploitation required for this vulnerability to cause harm.