CVE-2026-9255

Name: CVE-2026-9255
Creator: NVD / NIST
Published: 2026-05-22T17:16:49.767+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.4/10EPSS 0.12%

Last modified Jun 17, 2026

CVE-2026-9255 is a high-severity vulnerability rated 8.4/10 on the CVSS scale. 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.. EPSS estimates a 0.12% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

7.8/10

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

CVSS 4.0

8.4/10

CVSS:4.0/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

EPSS Probability

0.12%

2.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-862

Affected Software

Vendor	Product	Versions
Amazon	Kiro Cli	< 1.28.0

References

https://aws.amazon.com/security/security-bulletins/2026-035-aws/Vendor Advisory
https://kiro.dev/changelog/cli/1-28/Release Notes

Timeline

Published: May 22, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-9255?

How severe is CVE-2026-9255?

CVE-2026-9255 has a CVSS score of 8.4/10 (HIGH severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.

How do I fix CVE-2026-9255?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-9255?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST