CVE-2026-5429 PUBLISHED

Kiro IDE Webview Cross-Site Scripting via Workspace Color Theme

Assigner: AMZN
Reserved: 02.04.2026 Published: 02.04.2026 Updated: 02.04.2026

Unsanitized input during web page generation in the Kiro Agent webview in Kiro IDE before version 0.8.140 allows a remote unauthenticated threat actor to execute arbitrary code via a potentially damaging crafted color theme name when a local user opens the workspace. This issue requires the user to trust the workspace when prompted.

To remediate this issue, users should upgrade to version 0.8.140.

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS Score: 7.8

Attack Vector	Local	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 7.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	Present	Availability	High	Availability	None
Privileges Required	None
User Interaction	Active

CVSS 4.0

Product Status

Vendor	AWS
Product	Kiro IDE
Versions	Default: unaffected affected from 0.1 to 0.8.140 (excl.)

References

Problem Types

CWE-79 Improper neutralization of input during web page generation ('cross-site scripting') CWE

Impacts

CAPEC-63 Cross-Site Scripting (XSS)