open-webui Open WebUI up to 0.10.x KaTeX Renderer KatexRenderer.svelte cross site scripting

Summaryinfo

A vulnerability was found in open-webui Open WebUI up to 0.10.x. It has been declared as problematic. This issue affects some unknown processing of the file src/lib/components/chat/Messages/Markdown/KatexRenderer.svelte of the component KaTeX Renderer. Executing a manipulation can lead to cross site scripting. This vulnerability is tracked as CVE-2026-70492. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in open-webui Open WebUI up to 0.10.x. It has been declared as problematic. This vulnerability affects some unknown processing of the file src/lib/components/chat/Messages/Markdown/KatexRenderer.svelte of the component KaTeX Renderer. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. CVE summarizes:

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.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-70492 since 08/04/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 0.11.0 eliminates this vulnerability.

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Productinfo

Vendor

• open-webui

Name

• Open WebUI

Version

• 0.1
• 0.2
• 0.3
• 0.4
• 0.5
• 0.6
• 0.7
• 0.8
• 0.9
• 0.10

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CPE 2.2info

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