# CVE-2026-18657: Kiro IDE and CLI executable resolution from untrusted directory on Windows

Source: https://junglewise.ai/threats/cve-2026-18656-kiro-ide-and-cli-executable-resolution-from-untrusted-directory  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-04. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-18657 · Severity: high · CVSS 7.8 · Published 2026-08-04

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.

Technologies: [Amazon AWS](https://junglewise.ai/threats/technologies/aws), [AWS Kiro IDE](https://junglewise.ai/threats/technologies/kiro-ide), [Microsoft Windows](https://junglewise.ai/threats/technologies/windows). Vendors: [Amazon](https://junglewise.ai/threats/vendors/amazon), [AWS](https://junglewise.ai/threats/vendors/aws), [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-18657 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-18657 being exploited in the wild.

**How severe is CVE-2026-18657?** High severity, with a CVSS score of 7.8, published 4 August 2026.

**Which products and versions are affected?** AWS Kiro IDE <UNKNOWN>.

**Is there a fix for CVE-2026-18657?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-18657 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-18657?** Check whether you run Amazon AWS, AWS Kiro IDE or Microsoft Windows at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## 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>

## Identifiers

- CVE-2026-18657
- CVE-2026-18656

## Timeline

- 2026-09-09: disclosed

## References

- [https://aws.amazon.com/security/security-bulletins/rss/2026-074-aws/](https://aws.amazon.com/security/security-bulletins/rss/2026-074-aws/)

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