Executive brief
Kiro is a development environment (IDE and command-line tool) used by developers to build and test applications. On Windows systems, it has a flaw where it may run executable programs from the current project folder without verifying they are legitimate, allowing an attacker to place a malicious program in a project that gets executed when a developer opens it. This could lead to unauthorized access to the developer's machine, theft of source code or credentials, or use of the machine for further attacks.
Technical details
The vulnerability is a DLL/executable search path hijacking issue in Kiro IDE and CLI on Windows. When the tools attempt to resolve and execute external binaries, they search the untrusted project directory before checking system paths, violating the principle of least privilege. An attacker can exploit this by placing a malicious executable with a common name (e.g., a library or tool name) in a project directory; when a developer opens or builds the project, the malicious executable is invoked with the developer's privileges. The attack requires local access and user interaction (opening a malicious project), but no authentication. Two distinct CVE identifiers suggest the vulnerability may affect both the IDE and CLI components separately or in different code paths. Patches are likely available from the vendor.
Affected products
- AWS Kiro IDE <UNKNOWN>
- AWS Kiro CLI <UNKNOWN>
CVE identifiers
- CVE-2026-18657
- CVE-2026-18656
Timeline
- 2026-09-09: disclosed