CVE-2026-117616 in Jenkins Plugin
Summary
by MITRE • 10/28/2026
Jenkins 2.587 and earlier, LTS 2.580.1 and earlier provides an HTTP endpoint that loads agents by name without validating the name, allowing attackers with Overall/Read permission to load any config.xml file on the controller file system as an agent configuration, and to overwrite an arbitrary config.xml file when that agent is saved, potentially resulting in arbitrary code execution.
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Analysis
by VulDB Data Team • 10/28/2026
The vulnerability identified in Jenkins versions 2.587 and earlier, including LTS release 2.580.1 and prior iterations, represents a critical security flaw rooted in insufficient input validation within the HTTP endpoint responsible for loading agent configurations by name. This architectural weakness allows authenticated users possessing only Overall/Read permissions to manipulate the internal file system of the Jenkins controller through crafted requests. The core technical failure lies in the absence of path traversal checks or canonicalization when processing the agent name parameter, which is directly mapped to a file path on the server without sanitization. By exploiting this lack of validation, an attacker can specify paths that reference arbitrary locations within the controller's directory structure rather than restricting access to legitimate agent configuration directories.
This flaw enables two distinct and severe attack vectors depending on the specific interaction with the system. First, by loading a maliciously crafted config.xml file from any location on the disk where the Jenkins service has read permissions, an attacker can inject arbitrary code or modify existing configurations to achieve remote code execution. This is particularly dangerous because it bypasses standard authentication boundaries, as Overall/Read permission is typically granted to users who should only have limited visibility into the system. Second, when a user saves changes after loading such a file, the application overwrites an arbitrary config.xml on the filesystem with the attacker-controlled content. This write capability allows for persistent backdoors or complete compromise of the CI/CD pipeline infrastructure by altering build scripts, credentials storage mechanisms, or plugin configurations to execute malicious commands during subsequent builds.
From a classification perspective, this vulnerability aligns closely with CWE-22: Improper Limitation of a Pathname to a Restricted Directory, as it involves path traversal leading to unauthorized file access and modification. Furthermore, the exploitation technique maps directly to MITRE ATT&CK tactic T1059: Command and Scripting Interpreter, specifically through sub-techniques involving system-level commands or script execution via configuration manipulation. The ability to overwrite critical configuration files also relates to CWE-436: Interpretation Conflict, where the application interprets user-supplied input as a file path without proper validation, leading to unintended side effects such as arbitrary code execution.
The operational impact of this vulnerability is severe, potentially resulting in full compromise of the Jenkins controller and all connected build agents. Attackers can exfiltrate sensitive data stored within configuration files, including credentials, API tokens, and private keys. They can also disrupt service availability by corrupting essential system files or establish persistent access for future exploitation. Given that Jenkins often serves as a central hub for software development pipelines, compromising it can lead to supply chain attacks where malicious code is injected into legitimate builds distributed to downstream customers.
Mitigation strategies must prioritize immediate patching of the Jenkins instance to version 2.587 LTS or later, which addresses this input validation deficiency. In environments where upgrading is not immediately feasible, administrators should enforce strict network segmentation to restrict access to the Jenkins HTTP endpoint only from trusted IP ranges and implement robust web application firewalls that detect path traversal patterns in request parameters. Additionally, applying principle of least privilege by restricting Overall/Read permissions to essential personnel and auditing user roles can reduce the attack surface. Regular monitoring of file system integrity for unauthorized modifications to config.xml files is also recommended to detect potential exploitation attempts early.