Cross-site Scripting (XSS)Weakness · CWE-79

CVE-2026-39107

MEDIUM · 6.3 CVSS v3.1 Published 2026-06-03
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
Remotely reachable No privileges

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A Cross Site Scripting vulnerability exists in the Kimi AI v1.0 web interface's 'Preview' feature. The application fails to properly sanitize or encode HTML/JavaScript payloads generated by the AI model. When a user switches to the 'Preview' tab to view AI-generated code, the malicious payload is rendered directly into the DOM, leading to arbitrary JavaScript execution in the victim's browser session.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

A stored Cross Site Scripting vulnerability exists in Kimi AI v1.0's web interface 'Preview' feature. The application renders AI-generated content directly into the DOM without sanitizing or encoding HTML/JavaScript payloads, allowing arbitrary script execution when users view the Preview tab.

MitigationImplement context-appropriate output encoding and content sanitization (e.g., using a library like DOMPurify) on all AI-generated content before rendering in the Preview feature, ensuring HTML entities are properly escaped.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify the installed Kimi AI version
    Check the web interface version by looking at the application settings, about page, or checking the response headers for version information. Look for 'v1.0' or check the login/application URL for version indicators.
    Affected if The installed version is Kimi AI v1.0 specifically.
  2. Locate the Preview feature
    In the Kimi AI web interface, navigate to the feature where AI-generated content can be viewed. Look for a 'Preview' tab or toggle that switches from raw/code view to rendered view.
    Affected if The Preview tab exists and is accessible in the web interface.
  3. Test for reflected content rendering
    Generate content using the AI, then switch to the Preview tab. Inspect the DOM using browser developer tools (F12) to see if the content is rendered as raw HTML or if it's being processed by a sanitization library.
    Affected if Content appears directly in the DOM without visible encoding or sanitization markers.
  4. Check for sanitization in the application code
    Use browser developer tools to examine the JavaScript handling the Preview feature. Look for references to sanitization libraries like DOMPurify, or inspect network requests to see if content is processed server-side before rendering.
    Affected if No sanitization library (DOMPurify, sanitize-html, etc.) is loaded or referenced in the Preview feature code.

A user is affected if they are running Kimi AI v1.0 web interface, have access to the Preview feature, and the AI-generated content is rendered without any visible sanitization or encoding being applied.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Implement context-appropriate output encoding and content sanitization (e.g., using a library like DOMPurify) on all AI-generated content before rendering in the Preview feature, ensuring HTML entities are properly escaped.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing2.0 h
  • Review / QA1.0 h
9.0 hours of engineering $1,600
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Scan for this in your stack

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-39107 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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