CVE-2026-84658 in Script Security Plugin
Summary
by MITRE • 09/02/2026
Jenkins Script Security Plugin 1412.v7737b_3405f86 and earlier uses the `@DataBoundConstructor` annotation on a constructor that loads script approval configuration, allowing attackers able to submit certain forms to read that configuration.
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Analysis
by VulDB Data Team • 09/02/2026
The Jenkins Script Security Plugin version 1412.v7737b_3405f86 and earlier contains a critical information disclosure vulnerability rooted in the improper handling of Java annotations during object deserialization. Specifically, the plugin utilizes the @DataBoundConstructor annotation on a constructor responsible for loading script approval configuration data from user-submitted forms. In Jenkins, this annotation is typically intended to facilitate the binding of form input fields to class properties during normal administrative operations where trusted administrators configure security policies. However, in this specific implementation, the presence of this annotation inadvertently allows an attacker who can submit certain HTTP POST requests with crafted parameters to trigger the constructor logic outside its intended context. This bypasses standard access controls that would normally restrict such configuration changes to privileged users only.
The technical flaw lies in how Jenkins processes form submissions and maps them to internal objects via reflection. When a request is received, the framework inspects available constructors for the @DataBoundConstructor annotation and attempts to instantiate or update the object using provided parameters. Because the script approval configuration constructor was marked with this annotation without sufficient validation of the caller's permissions or context, an unauthenticated attacker or a low-privileged user can manipulate these form fields. By supplying specific input values that correspond to internal properties of the security configuration class, the attacker forces the system to execute code paths designed for administrative setup rather than simple data processing. This results in the unintended reading and potentially exposing sensitive details about how scripts are approved within the Jenkins environment.
The operational impact of this vulnerability is significant as it leads to a violation of confidentiality regarding the internal security posture of the Jenkins instance. Script approval configurations dictate which Groovy scripts or methods are permitted to run, effectively acting as an allow-list for code execution. By reading this configuration through the described flaw, attackers can gain insight into which specific functions and libraries have been whitelisted by administrators. This intelligence is crucial for subsequent exploitation phases, allowing adversaries to identify potential attack vectors that bypass existing security controls. For instance, knowing approved methods enables an attacker to craft malicious scripts that leverage these trusted components, thereby increasing the likelihood of successful code execution or privilege escalation without triggering immediate alerts associated with unapproved script usage.
This vulnerability aligns with CWE-200, which classifies Information Exposure, as it involves the leakage of sensitive internal state information through improper access control mechanisms. Furthermore, from a tactical perspective related to the MITRE ATT&CK framework, this flaw facilitates Reconnaissance activities, specifically within the category of Gather Victim Host Information or Application Data Discovery. The attacker leverages the misconfigured annotation to extract data that aids in mapping out the system's security boundaries and trusted execution paths. This step is often a precursor to more severe attacks such as Command Injection or Privilege Escalation, where understanding the allowed script methods provides a roadmap for bypassing defenses.
To mitigate this risk, organizations running Jenkins with affected versions of the Script Security Plugin must upgrade immediately to version 1412.v7737b_3405f86 or later, where the constructor has been properly secured against unauthorized invocation via form binding. In addition to patching, administrators should review their instance for any signs of unauthorized access attempts that may have exploited this flaw prior to remediation. It is also advisable to enforce strict network segmentation and ensure that Jenkins instances are not exposed directly to untrusted networks without robust authentication mechanisms in place. Regular audits of script approval lists can further reduce the blast radius if such vulnerabilities are discovered, ensuring that only strictly necessary scripts are permitted to run within the CI/CD pipeline environment.