Vulnerability · Published May 22, 2026 · Assigned by AMZN
CVE-2026-9255Tool Execution Without Authorization via Piped Stdin in Kiro CLI
High 7.8
In plain English
A high-severity missing authorization in Kiro CLI from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities).
Severity (CVSS 3.1)7.8High
Exploit odds (30 days)0.1%top 98.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Missing input source validation in the tool authorization prompt in Kiro CLI before 1.28.0 allows a local attacker to execute arbitrary tools, including shell commands, without user approval by crafting content that is piped to kiro-cli via stdin. We recommend you to upgrade to kiro-cli version 1.28.0 or later.
Affected products (as reported)
Weakness: CWE-862 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
References
- https://kiro.dev/changelog/cli/1-28/ release-notes
- https://aws.amazon.com/security/security-bulletins/2026-035-aws/ vendor-advisory