| 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) | 2026-06-23 |
| Last modified | 2026-06-25 |
| Affected versions | open_webui < 0.9.6 |
| Fixed in | 0.9.6 |
| Weakness | CWE-79 |
| CISA KEV | not listed |
NVD description
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.6,Open WebUI renders Mermaid blocks from Markdown files in the file preview panel and inserts the generated SVG into the DOM using innerHTML. Because Mermaid is configured with securityLevel: 'loose', attacker-controlled Mermaid content can be rendered unsafely in this flow. A working payload was validated through the Markdown preview path, resulting in JavaScript execution in the victim’s browser under the application origin. This vulnerability is fixed in 0.9.6.
What to do
- Upgrade Open WebUI to
0.9.6or later. - Do not expose the component's API or UI to the internet without authentication in front of it.
Sources
Read more
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