Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages

SummaryAny authenticated user can store a chat message whose math block makes KaTeX fail with a stack overflow instead of a parse error. When that happens the renderer falls back to inserting the original math source into the page as HTML rather than as text, so script in the message runs in the...

Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages

Summary Any authenticated user can store a chat message whose math block makes KaTeX fail with a stack overflow instead of a parse error. When that happens the renderer falls back to inserting the original math source into the page as HTML rather than as text, so script in the message runs in the...

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

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. Th...