| Component | Open WebUI |
| Severity | high (CVSS 8.7) |
| CVSS vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N |
| Published (NVD) | 2026-08-04 |
| Last modified | 2026-09-18 |
| Affected versions | open_webui >= 0.10.0, < 0.11.0 |
| Fixed in | 0.11.0 |
| Weakness | CWE-79 |
| CISA KEV | not listed |
NVD 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.
What to do
- Upgrade Open WebUI to
0.11.0or later. - Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
- NVD: CVE-2026-70492
- https://github.com/open-webui/open-webui/pull/26718
- https://github.com/open-webui/open-webui/security/advisories/GHSA-pwxh-7358-jq2x
- https://github.com/open-webui/open-webui/commit/bc600d3f085802c45aa8f38c30e6e8c986bde6cc
- https://github.com/open-webui/open-webui/releases/tag/v0.11.0
Read more
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