CVE-2026-49483 in Code for IBMi Plugin
Summary
by MITRE • 10/13/2026
Code for IBMi is a Visual Studio Code extension for maintaining and compiling ILE languages on the IBMi platform. Prior to 3.0.1, IBMi components implementing IBMiComponent were accepted after checking that a procedure existed without reliably verifying component integrity. Components installed with broad public permissions allow another local account to alter a program such as GETMBRINFO. A later connection can execute the altered program under the connecting account because the LONG_COMMENT marker alone does not establish integrity. This issue is fixed in version 3.0.1.
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Analysis
by VulDB Data Team • 10/13/2026
The vulnerability identified within Code for IBMi versions prior to 3.0.1 represents a critical failure in software supply chain security and component validation mechanisms. As an extension designed to maintain and compile ILE languages on the IBM i platform, it relies heavily on external components known as IBMiComponents. The core technical flaw lies in the integrity verification process during installation or loading of these components. Specifically, the system checks for the existence of a procedure within the component but fails to perform reliable cryptographic or structural validation of the component's actual content. This oversight means that while the extension confirms a required function is present, it does not guarantee that the rest of the code has remained unaltered since its original creation by the vendor.
This lack of integrity verification becomes particularly dangerous when combined with insufficient file system permissions on the IBM i operating system. Components installed with broad public write permissions allow any local user account to modify the binary or source files associated with these components. For instance, a malicious actor could alter a program such as GETMBRINFO by injecting arbitrary code or modifying existing logic. Because the extension relies solely on the presence of specific markers like LONG_COMMENT rather than robust integrity checks such as digital signatures or hash verification, it accepts this tampered version without raising an alarm. The system assumes that if the marker exists and the procedure is callable, the component is safe to use.
The operational impact of this vulnerability allows for privilege escalation and arbitrary code execution under the context of the connecting account. When a user subsequently connects to the IBM i environment using Code for IBMi, the extension loads the compromised components. Since these components are executed with the privileges of the authenticated user, an attacker who previously modified the component can effectively execute malicious commands or data exfiltration scripts as that user. This creates a significant risk of unauthorized access, data theft, and potential compromise of broader system resources if the connecting account holds elevated permissions. The attack vector is local but requires physical or logical access to modify files with public write rights, making it viable in environments where strict file permission policies are not enforced.
From a classification perspective, this vulnerability aligns closely with CWE-354, which describes improper validation of integrity checks during software installation. It also relates to CWE-732, concerning insufficient permissions for critical system files or components. In the context of the MITRE ATT&CK framework, this scenario facilitates techniques associated with Tactic TA0001 (Initial Access) and potentially TA0004 (Privilege Escalation), as an attacker modifies a trusted application to gain unauthorized execution rights under a legitimate user account. The failure to implement secure coding practices regarding component verification highlights the importance of defense-in-depth strategies in development tools that interact with operating system resources.
To mitigate this vulnerability, organizations must immediately upgrade Code for IBMi to version 3.0.1 or later, where the integrity verification logic has been corrected to ensure components are validated beyond mere procedure existence checks. Additionally, administrators should enforce strict file permission policies on the IBM i platform, ensuring that critical component directories do not have broad public write access. Implementing digital signature validation for all loaded extensions and components would further prevent tampering. Regular audits of installed software integrity using cryptographic hashes can also serve as a compensating control to detect unauthorized modifications before they are executed by users or automated processes.