Vulnerability · Published Apr 2, 2026 · Assigned by AMZN

CVE-2026-5429Kiro IDE Webview Cross-Site Scripting via Workspace Color Theme

High 7.8

In plain English

A high-severity cross-site scripting in Kiro IDE from AWS. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities).

Severity (CVSS 3.1)7.8High

Exploit odds (30 days)0.2%top 94.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
AWS	Kiro IDE	0.1 – before 0.8.140

Weakness: CWE-79 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

https://aws.amazon.com/security/security-bulletins/2026-012-aws/ vendor-advisory
https://kiro.dev/changelog/ide/0-8/#patch-0-8-140 release-notes