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PatchSiren cyber security CVE debrief

CVE-2026-9255 AWS CVE debrief

CVE-2026-9255 is a HIGH severity vulnerability in Kiro CLI versions prior to 1.28.0. The issue arises from missing input source validation in the tool authorization prompt, allowing a local attacker to execute arbitrary tools or shell commands without user approval by manipulating input piped to kiro-cli via stdin. The vulnerability has a CVSS score of 8.4.

Vendor
AWS
Product
Kiro CLI
CVSS
HIGH 8.4
CISA KEV
Not listed in stored evidence
Original CVE published
2026-05-22
Original CVE updated
2026-07-23
Advisory published
2026-05-22
Advisory updated
2026-07-23

Who should care

Users of Kiro CLI versions prior to 1.28.0, administrators of systems where Kiro CLI is used, and security teams responsible for vulnerability management.

Technical summary

The vulnerability is caused by a lack of input validation in the tool authorization prompt of Kiro CLI. This allows an attacker to execute arbitrary tools or shell commands by crafting input that is piped to kiro-cli via stdin, potentially leading to unauthorized command execution.

Defensive priority

HIGH

Recommended defensive actions

  • Upgrade to Kiro CLI version 1.28.0 or later to address the vulnerability.
  • Restrict access to Kiro CLI to trusted users and ensure that input is validated before execution.
  • Monitor systems using Kiro CLI for suspicious activity.

Evidence notes

The CVE-2026-9255 details were obtained from the official CVE record and NVD database.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-9255 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-9255

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-9255 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-9255

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Supplemental references

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://aws.amazon.com/security/security-bulletins/2026-035-aws/

    ff89ba41-3aa1-4d27-914a-91399e9639e5 - Vendor Advisory

  • Mitigation or vendor reference

    Unverified legacy reference

    URL: https://kiro.dev/changelog/cli/1-28/

    ff89ba41-3aa1-4d27-914a-91399e9639e5 - Release Notes

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.