CVE-2026-4295

High

Published: 17 March 2026

Published

17 March 2026

Modified

18 March 2026

KEV Added

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Patch

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CVSS Score 7.8 CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS Score 0.0002 4.7th percentile

Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2026-4295 is a high-severity Inclusion of Functionality from Untrusted Control Sphere (CWE-829) vulnerability in Amazon (inferred from references). Its CVSS base score is 7.8 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked at the 4.7th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified are NIST 800-53 AC-4 (Information Flow Enforcement) and SI-2 (Flaw Remediation).

Threat & Defense at a Glance

What attackers do: exploitation maps to Exploitation for Client Execution (T1203) and 1 other technique. What defenders deploy: see the NIST 800-53 controls recommended below.

Threat & Defense Details

Mitigating Controls (NIST 800-53 r5)AI

SI-2 Flaw Remediation good match

prevent

Directly addresses the vulnerability by requiring timely remediation through upgrading Kiro IDE to version 0.8.0 or higher to fix the improper trust boundary enforcement.

AC-4 Information Flow Enforcement good match

prevent

Enforces information flow control policies to prevent malicious project directory files from bypassing workspace trust boundaries and accessing trusted execution contexts.

AC-3 Access Enforcement partial match

prevent

Mandates enforcement of access authorizations that counter the improper logical access controls exploited by crafted project files in Kiro IDE.

MITRE ATT&CK Enterprise TechniquesAI

T1203 Exploitation for Client Execution Execution

Adversaries may exploit software vulnerabilities in client applications to execute code.

attack.mitre.org →

T1204.002 Malicious File Execution

An adversary may rely upon a user opening a malicious file in order to gain execution.

attack.mitre.org →

Why these techniques?

Vulnerability in IDE client directly enables exploitation for client-side code execution (T1203) via user opening malicious project directory files that bypass trust protections (T1204.002).

Confidence: HIGH · MITRE ATT&CK Enterprise v18.1

NVD Description

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.

Deeper analysisAI

CVE-2026-4295 is an improper trust boundary enforcement vulnerability (CWE-829) affecting Kiro IDE versions prior to 0.8.0 across all supported platforms. The flaw enables maliciously crafted project directory files to bypass workspace trust protections, potentially allowing arbitrary code execution when a local user opens the directory.

A remote unauthenticated threat actor can exploit this vulnerability by tricking a user into opening a malicious project directory. Exploitation requires local access (AV:L), low attack complexity (AC:L), no privileges (PR:N), and user interaction (UI:R), resulting in high confidentiality, integrity, and availability impacts (C:H/I:H/A:H) with unchanged scope (S:U), as scored at CVSS 7.8 (CVSS:3.1).

Advisories recommend upgrading to Kiro IDE version 0.8.0 or higher to remediate the issue, as detailed in the AWS security bulletin (2026-009-AWS) and the Kiro IDE changelog.