8.4
HIGH CVSS 4.0
CVE-2026-9255
Tool Execution Without Authorization via Piped Stdin in Kiro CLI
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.

INFO

Published Date :

May 22, 2026, 4:38 p.m.

Last Modified :

May 22, 2026, 4:42 p.m.

Remotely Exploit :

No

Source :

AMZN
Affected Products

The following products are affected by CVE-2026-9255 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

No affected product recoded yet

CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 HIGH ff89ba41-3aa1-4d27-914a-91399e9639e5
CVSS 4.0 HIGH ff89ba41-3aa1-4d27-914a-91399e9639e5
Solution
Upgrade kiro-cli to version 1.28.0 or later to fix authorization bypass.
  • Upgrade kiro-cli to version 1.28.0 or later.
  • Validate tool authorization prompts and input sources.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-9255 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-9255 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by ff89ba41-3aa1-4d27-914a-91399e9639e5

    May. 22, 2026

    Action Type Old Value New Value
    Added 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.
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
    Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
    Added CWE CWE-862
    Added Reference https://aws.amazon.com/security/security-bulletins/2026-035-aws/
    Added Reference https://kiro.dev/changelog/cli/1-28/
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.