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 9:45 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 Resolution: This issue has been addressed in kiro-cli version 1.28.0 . We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. Workarounds: Run kiro-cli with the --no-interactive flag when piping content from untrusted sources. This explicitly disables tool approval prompts and prevents piped input from being consumed as confirmation responses. References: CVE-2026-9255 Please email aws-security@amazon.com with any security questions or concerns.   "},"metadata":{"tags":[]}},{"fields":{"patternBoolean2":"false","id":"ams#rt-rich-textc2#pattern-data"},"metadata":{"tags":[{"name":"pattern-data","description":"Default pattern data","id":"ams#rt-rich-textc2#pattern-data","namespaceId":"rt-rich-text"}]}}]},"metadata":{"auth":{},"testAttributes":{}},"context":{"page":{"pageUrl":"https://aws.amazon.com/security/security-bulletins/2026-035-aws/"},"contentType":"page","environment":{"stage":"prod","region":"us-west-2"},"sdkVersion":"2.0.27"},"refMap":{"manifest.js":"cda3e8d042","rt-rich-text.rtl.css":"6a04028f86","rt-rich-text.css":"98f5a6aee4","rt-rich-text.js":"b5a4d764a3","rt-rich-text.css.js":"3d619cc2e1","rt-rich-text.rtl.css.js":"ccdb945d3e"},"settings":{"templateMappings":{"patternHeading":"patternHeading","patternSubheading":"patternSubheading","patternDark":"patternBoolean2","title":"itemHeading","bodyText":"itemLongLoc"}}} 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 9:45 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 Resolution: This issue has been addressed in kiro-cli version 1.28.0 . We recommend upgrading to the latest version and ensuring any forked or derivative code is patched to incorporate the new fixes. Workarounds: Run kiro-cli with the --no-interactive flag when piping content from untrusted sources. This explicitly disables tool approval prompts and prevents piped input from being consumed as confirmation responses. References: CVE-2026-9255 Please email aws-security@amazon.com with any security questions or concerns.   {"data":{"items":[{"fields":{"footer":"{ "createAccountButtonLabel": "Create an AWS account", "createAccountButtonURL": "https://signin.aws.amazon.com/signup?request_type=builderId", "backToTopText": "Back to top", "eoeText": "Amazon is an equal opportunity employer and does not discriminate on the basis of protected veteran status, disability or other legally protected status. Veterans, military spouses, and people with disabilities are encouraged to apply.", "copyrightText": "© 2026, Amazon Web Services, Inc. or its affiliates. All rights reserved.", "items": [ { "name": "Learn", "linkURL": "", "items": [ { "heading": "What Is AWS?", "linkURL": "/what-is-aws/?nc1=f_cc" }, { "heading": "What Is Cloud Computing?",

Severity from

NVD

• aws.amazon.com/security/security-bulletins/rss/2026-035-aws/
• www.cve.org/CVERecord?id=CVE-2026-9255