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CVE-2026-70492

CVE-2026-70492 · Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages

This page contains facts from public vulnerability sources. Check the original advisory before updating.

Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.0, src/lib/components/chat/Messages/Markdown/KatexRenderer.svelte could store and render a chat message whose math block makes KaTeX fail with a stack overflow instead of a parse error. The catch branch fell back to inserting the original math source into the page as HTML through {@html} rather than as text, so script in the message runs in the browser of whoever views it, including shared chats and channels. The viewer's session token in localStorage can be stolen, and an administrator viewer can have their account taken over. This issue is fixed in 0.11.0.

CVSS 8.7 · High · EPSS 0.4% · Fix available

Published
Updated

Stack: python

Affected products and versions

  • open-webui

    Versions
    • >= 0.10.0, < 0.11.0: Affected

    No fix published

  • open-webui PyPI

    Versions
    • 0.10.0
    • 0.10.1
    • 0.10.2
    Affected ranges
    • ECOSYSTEM: ≥ 0.10.0, < 0.11.0

    Update to 0.11.0

Original sources

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