Skip to main content

Kiro Ide EUVDEUVD-2026-18519

| CVE-2026-5429 HIGH
Cross-site Scripting (XSS) (CWE-79)
2026-04-02 AMZN GHSA-7v7j-vpv5-h468
7.1
CVSS 4.0 · Vendor: AMZN
View

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Craft malicious color theme name
  2. Delivery
    Distribute workspace with payload
  3. Exploit
    User opens workspace and trusts prompt
  4. Execution
    Unsanitized input injected into webview
  5. Impact
    Arbitrary code execution in Kiro Agent

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Output encoding, context-aware escaping
MITRE ATT&CK

2 techniques across 2 tactics: Initial Access, Execution

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Kiro IDE versions before 0.8.140. Attacker crafts a malicious workspace with a specially-crafted color theme name. Local user must open the workspace and click 'trust' when prompted. Remote attacker delivers the workspace file to the victim.

Impact

Real-world risk assessment reveals moderate overall threat despite the 7.1 CVSS score and high impact ratings. The CVSS 4.0 vector shows this requires local access (AV:L), active user participation (UI:A), and specific preconditions (AT:P-user must trust the workspace). SSVC framework confirms exploitation status as 'none' with 'no' automatable capability, meaning attacks require social engineering to convince users to open and trust malicious workspace files-this cannot be weaponized into wormable or mass-exploitation campaigns. The 'total' technical impact rating (VC:H/VI:H/VA:H) reflects that successful exploitation grants full system compromise within the IDE's security context. No EPSS score is provided, but the combination of required user interaction, workspace trust prompt, and lack of public exploit code suggests low probability of widespread exploitation. This represents a supply chain risk vector where malicious actors could distribute trojanized Kiro IDE workspace files via Git repositories or shared project templates, similar to historical VSCode extension attacks. Priority should be elevated for organizations using Kiro IDE in collaborative development environments where workspace files are routinely shared, but remains lower than remotely exploitable vulnerabilities or those with confirmed active exploitation.

Exploit ScenarioDerived

An attacker creates a malicious Kiro IDE workspace configuration with a specially crafted color theme name containing JavaScript payload, then distributes this workspace via a public GitHub repository advertising useful development tools or project templates. When a developer clones the repository and opens it in vulnerable Kiro IDE versions, the IDE prompts for workspace trust-a common occurrence developers often accept reflexively. Upon granting trust, the Kiro Agent webview renders the malicious theme name without sanitization, executing the embedded JavaScript with full IDE privileges, allowing the attacker to exfiltrate source code, inject backdoors into build pipelines, or establish persistence through IDE extension installation.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.0% exploitation probability (EPSS)

Get an e-mail when this CVE is exploited, patched or re-scored. Free account.

Alert me

AnalysisAIv1 – Apr 02, 2026

Arbitrary code execution in AWS Kiro IDE versions prior to 0.8.140 occurs when a local user opens a maliciously crafted workspace containing an unsanitized color theme name, exploiting improper neutralization of input during webview generation. The attack requires user interaction (trusting the workspace when prompted) and can deliver full system compromise with high confidentiality, integrity, and availability impact. No public exploit identified at time of analysis, though SSVC framework rates technical impact as total with manual (non-automatable) exploitation potential.

RemediationAI

Upgrade immediately to AWS Kiro IDE version 0.8.140 or later, which contains input sanitization fixes for webview rendering of workspace configuration parameters. The official patch is documented in the Kiro IDE changelog at https://kiro.dev/changelog/ide/0-8/#patch-0-8-140 with implementation details available in AWS Security Bulletin 2026-012 at https://aws.amazon.com/security/security-bulletins/2026-012-aws/. Organizations unable to upgrade immediately should implement compensating controls including restricting workspace sources to trusted internal repositories, enforcing mandatory security reviews of workspace configuration files before distribution, and educating developers to scrutinize workspace trust prompts especially when opening projects from external or unknown sources. Disable automatic workspace trust features if available in older versions and require explicit administrator approval for workspace activation in sensitive development environments.

Affected VersionsENISA

Kiro IDE 0.1 <0.8.140

Affected Packages

euvd kiro_ide fix: 0.8.140

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability stems from CWE-79 (Improper Neutralization of Input During Web Page Generation, commonly known as Cross-Site Scripting) affecting the Kiro Agent webview component within AWS Kiro IDE. The affected component fails to sanitize user-controlled input in workspace configuration files-specifically color theme names-before rendering them in the IDE's webview interface. While classified as XSS, the technical impact escalates to arbitrary code execution because the webview operates within the Electron-like IDE environment with access to native system APIs. The CPE identifier (cpe:2.3:a:aws:kiro_ide) confirms this affects AWS's Kiro IDE product across all versions from 0.1 through builds preceding 0.8.140. The CVSS 4.0 vector indicates local attack vector (AV:L) requiring user interaction (UI:A) with present attack complexity (AT:P), meaning the attack depends on specific timing or conditions-in this case, the user explicitly trusting the malicious workspace.

Know when Kiro Ide gets its next vulnerability

  • Watch products and get an email when something new is published
  • Check this CVE against your own stack and servers
  • Exploit and PoC references, threat intelligence from 22 sources

No credit card · 7-day full trial

Severity by source

Vendor (AMZN) PRIMARY 7.1 HIGH
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

Primary rating from Vendor (AMZN) · only source for this CVE.

CVSS VectorVendor: AMZN

Attack Vector
Local
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
Active
Vulnerable system: Confidentiality
High
Vulnerable system: Integrity
High
Vulnerable system: Availability
High
Subsequent system: Confidentiality
None
Subsequent system: Integrity
None
Subsequent system: Availability
None

Lifecycle Timeline

3
Analysis Updated
Apr 16, 2026 - 06:08 EUVD-patch-fix
executive summary
Patch available
Apr 16, 2026 - 05:29 EUVD
0.8.140
CVE Published
Apr 02, 2026 - 18:37 nvd
HIGH 7.1

DescriptionCVE.org

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.

Executive ViewAI

Why It Matters

AWS Kiro IDE versions before 0.8.140 contain an arbitrary code execution vulnerability triggered when users open malicious workspace files with crafted color theme names, requiring user interaction but potentially delivering full system compromise. Development and engineering teams using affected Kiro IDE versions face elevated risk of code injection attacks delivered through workspace sharing or supply chain vectors. Immediate patching is critical to prevent local privilege escalation and unauthorized access to development environments and source code repositories.

Business Impact: High
Compensating Controls

Apply vendor patch to version 0.8.140 or later. Interim mitigations pending patching: restrict workspace file access to pre-vetted internal sources only; disable or sandbox Kiro IDE on systems handling sensitive code until patching is complete; implement file integrity monitoring on workspace configuration files; mandate user security awareness training on risks of opening untrusted workspace files.

Threat Intelligence Overview

EPSS Score
0.0%
Top 94% exploitable
Data Quality
6 sources
Confidence: High

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.0%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Small
Automatable
No
Human Impact
High
Technical Impact
Total

Priority Score

36
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +36
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

Cross-Site Scripting occurs when an application accepts untrusted data and sends it to a web browser without proper validation or encoding.

Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy