CVE-2026-9255 - Tool Execution Without Authorization via Piped Stdin in Kiro CLI

Bulletin ID: 2026-035-AWS Scope: AWS Content Type: Important (requires attention) Publication Date: 05/22/2026 09:45 AM PDT Description: Kiro CLI is a command-line AI coding assistant that enables developers to interact with AI models to execute code, manage files, and run shell commands. We identified CVE-2026-9255, an issue where missing input source validation in the tool authorization prompt could allow a local actor to execute arbitrary tools, including shell commands, without user approval by crafting content that is piped to kiro-cli via stdin. Impacted versions: kiro-cli prior to 1.28.0 Please refer to the article below for the most up-to-date and complete information related to this AWS Security Bulletin.