VULNERABILITY INTELLIGENCE

CVE-2026-70492

CVSS score8.7 HIGH
EPSS probability0.40%
CISA KEVNot currently listed
Published2026-08-04
Last modified2026-09-18
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

Description

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.

Weakness classification

  • CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Primary references