CVE-2026-5429 Kiro IDE Webview Cross-Site Scripting via Workspace Color Theme
Remote attackers can execute arbitrary code in Kiro IDE via a crafted color theme name when a user opens a trusted workspace.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-5429?
CVE-2026-5429 is a high-severity cross-site scripting vulnerability in AWS Kiro IDE, published on 2 Apr 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
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.
Weakness: CWE-79
Which versions are affected by CVE-2026-5429?
How do I fix CVE-2026-5429?
No fix has been published for CVE-2026-5429 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-5429 being exploited?
There is no known exploitation of CVE-2026-5429 in the wild and no public exploit code.
Sources
Also known as GHSA-7v7j-vpv5-h468.