CVE-2026-92129 in Script Security Plugin
Summary
by MITRE • 09/16/2026
Jenkins Script Security Plugin 1415.v9a_f9b_3a_c253d and earlier does not check calls from sandboxed scripts to methods added dynamically to a class at runtime, allowing attackers with permission to define and run sandboxed scripts, including Pipelines, to bypass the sandbox protection and execute code outside the sandbox.
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Analysis
by VulDB Data Team • 09/16/2026
The Jenkins Script Security Plugin serves as a critical defense mechanism for Jenkins automation servers by enforcing strict execution policies on Groovy scripts through its sandbox environment. This plugin is designed to prevent untrusted or partially trusted users from executing arbitrary Java methods that could compromise system integrity, access sensitive data, or perform unauthorized administrative actions. The vulnerability identified in versions 1415.v9a_f9b_3a_c253d and earlier stems from a fundamental flaw in how the sandbox enforcement logic handles dynamic method invocation. Specifically, when scripts operate within the restricted sandbox environment, they are typically limited to a whitelist of allowed methods. However, the implementation failed to adequately validate calls directed at methods that were added dynamically to existing classes during runtime execution rather than being present as static members defined at compile time. This oversight creates a significant gap in the security boundary intended by the sandbox architecture.
From a technical perspective, this flaw allows an attacker who possesses permission to define and execute sandboxed scripts, such as those used in Jenkins Pipelines, to bypass these restrictions entirely. By leveraging Java reflection capabilities or dynamic class manipulation techniques available within Groovy, an adversary can inject new methods into classes at runtime and subsequently invoke them from their script context. Because the security plugin did not check whether these dynamically added methods were safe for sandboxed execution, it permitted calls that would otherwise be blocked if they had been part of the original static method signature. This effectively nullifies the protective measures provided by the Script Security Plugin, allowing code to execute with higher privileges than intended and outside the constraints of the security sandbox.
The operational impact of this vulnerability is severe for organizations relying on Jenkins for continuous integration and deployment workflows. An attacker exploiting this issue can achieve arbitrary code execution within the context of the Jenkins controller process. This level of access enables a wide range of malicious activities, including reading sensitive configuration files, stealing credentials stored in Jenkins credential stores, modifying build configurations to inject malware into software artifacts, or pivoting further into the internal network from the compromised server. Since Jenkins often holds elevated privileges and deep integration with development tools and infrastructure, compromising it can lead to widespread disruption of delivery pipelines and potential exposure of intellectual property. The vulnerability is particularly dangerous because it affects users who believe they are operating safely within a restricted sandbox environment, leading to false confidence in their security posture.
This issue aligns with CWE-284 Improper Access Control, as the system fails to properly restrict access to resources based on user permissions and execution context. Furthermore, from an adversary perspective, this vulnerability facilitates techniques associated with MITRE ATT&CK T1059 Command and Scripting Interpreter, specifically allowing for the abuse of legitimate scripting environments like Groovy within Jenkins to execute unauthorized commands. It also relates to CWE-472 External Control of Default Value in Security-Critical Code, as the dynamic nature of the method addition bypasses static security checks designed to control default execution paths.
To mitigate this risk, organizations must immediately upgrade the Script Security Plugin to version 1415.v9a_f9b_3a_c253d or later, where these runtime validation gaps have been addressed by developers. In environments where immediate patching is not feasible due to compatibility constraints with other plugins, administrators should rigorously audit pipeline scripts and restrict who has the ability to create or modify Jenkinsfiles. Implementing strict least-privilege principles for user roles within Jenkins can limit the blast radius if an account is compromised. Additionally, enabling detailed logging of script execution events allows security teams to monitor for anomalous patterns indicative of sandbox escape attempts, such as unusual reflection usage or dynamic class manipulation signatures. Regular vulnerability scanning and adherence to vendor-recommended update schedules are essential practices to maintain a robust defense against evolving threats targeting automation infrastructure.