CVE-2026-18657 in CLI
Summary
by MITRE • 08/04/2026
An uncontrolled search path element in Kiro CLI before version 2.10.0 on Windows might allow a remote unauthenticated actor to execute arbitrary code via a maliciously crafted project directory containing an executable that bypasses workspace trust protections when a local user starts Kiro CLI in the directory.
To remediate this issue, users should upgrade to version 2.10.0 or higher.
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Analysis
by VulDB Data Team • 08/04/2026
This vulnerability represents a classic path traversal and privilege escalation flaw that exploits the Windows command execution environment through improper handling of search paths in the Kiro CLI tool. The security weakness stems from the application's failure to properly sanitize or validate executable paths when processing project directories, creating an opportunity for remote attackers to inject malicious code into the system execution flow. The vulnerability specifically affects versions prior to 2100 and demonstrates a critical design flaw in how the tool manages workspace trust mechanisms on Windows platforms.
The technical implementation of this vulnerability involves the exploitation of the PATH environment variable handling within the Kiro CLI application. When a local user executes the CLI tool within a maliciously crafted project directory, the application searches through the directory path to locate required executables without proper validation of the search path elements. This behavior allows an attacker to place a malicious executable with the same name as a legitimate tool in the project directory, causing the CLI to execute the attacker-controlled binary instead of the intended system utility. The flaw operates at the operating system level where the command resolution process does not adequately distinguish between trusted and untrusted executables within the project context.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential privilege escalation scenarios, as the malicious executable would run with the privileges of the local user who initiated the Kiro CLI process. This represents a significant concern for environments where users may have elevated permissions or where the tool is used in automated workflows. The vulnerability enables remote attackers to bypass existing workspace trust protections that are typically designed to prevent execution of untrusted code from project directories, effectively undermining the security controls that should protect against malicious code injection.
This issue aligns with CWE-427 Uncontrolled Search Path Elements and follows patterns commonly associated with path traversal vulnerabilities in command-line interfaces. The ATT&CK framework categorizes this as a technique involving Execution through API and potentially Privilege Escalation through Application Shimming or DLL Side-Loading mechanisms. Organizations should consider implementing application whitelisting policies, monitoring for suspicious executable behavior in project directories, and ensuring that all system components are updated to versions that properly address these search path vulnerabilities. The remediation strategy of upgrading to version 2100 or higher addresses the core issue by implementing proper search path validation and ensuring that workspace trust protections function as intended, preventing the execution of unauthorized binaries from potentially compromised project directories.