CVE-2026-4295 in AWS Kiro IDE
Summary
by MITRE • 03/17/2026
Improper trust boundary enforcement in Kiro IDE before version 0.8.0 on all supported platforms might allow a remote unauthenticated threat actor to execute arbitrary code via maliciously crafted project directory files that bypass workspace trust protections when a local user opens the directory.
To remediate this issue, users should upgrade to version 0.8.0 or higher.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 03/21/2026
This vulnerability represents a critical trust boundary violation in the Kiro IDE software that affects all supported platforms prior to version 0.8.0. The flaw manifests when a local user opens a maliciously crafted project directory that contains specially designed files intended to bypass the workspace trust protections that are normally enforced by the application. This represents a classic case of insufficient input validation and trust boundary enforcement that falls under CWE-501, which specifically addresses trust boundary violations where the system fails to properly validate or enforce security boundaries between trusted and untrusted components.
The technical implementation of this vulnerability exploits the application's failure to properly validate project directory contents when establishing workspace trust levels. When a user opens a directory, the IDE should enforce strict validation of all files within that directory to ensure they originate from trusted sources and do not contain malicious code or instructions designed to exploit the application's trust model. However, the vulnerability allows threat actors to craft project files that appear legitimate but contain embedded malicious code or instructions that bypass these trust protections, creating a scenario where unauthenticated remote attackers can potentially execute arbitrary code on the target system.
The operational impact of this vulnerability is significant as it enables remote code execution without requiring authentication or user interaction beyond simply opening a malicious directory. This creates a particularly dangerous attack vector because it can be exploited through social engineering campaigns where users are tricked into opening malicious project directories, or through automated exploitation mechanisms. The vulnerability essentially allows attackers to gain arbitrary code execution privileges on the victim's system with the same privileges as the user running the IDE, potentially leading to complete system compromise, data exfiltration, or further network lateral movement. This aligns with ATT&CK technique T1059 which covers command and scripting interpreter usage, and T1566 which covers credential harvesting through social engineering.
The vulnerability's exploitation pathway demonstrates a failure in the application's security model where the trust boundary between the user's local environment and potentially malicious project files is improperly enforced. Attackers can leverage this weakness by creating project directories with malicious files that, when opened by the IDE, trigger code execution before the application can properly validate the trust level of the workspace. This represents a failure in the principle of least privilege and proper sandboxing of untrusted content, where the application should isolate potentially malicious files and prevent them from executing code within the context of the trusted IDE environment. The remediation approach of upgrading to version 0.8.0 or higher addresses this by implementing proper trust boundary enforcement mechanisms that validate all project directory contents and prevent malicious files from bypassing workspace security protections, effectively closing the attack vector that allowed remote code execution through crafted project files.