CVE-2026-109300
Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds
- State
- Published
- Severity
- 5.1 Medium
- Published
- Oct 12, 2026
- Updated
- Oct 13, 2026
- Reserved
- Oct 12, 2026
Description
Open WebUI from 0.6.31 before 0.11.4 contains a stored cross-site scripting vulnerability in its Markdown renderer, which treats user-authored tool-call details blocks as tool output and mounts their embeds attribute in script-enabled iframes. Authenticated users can post crafted channel messages, chat messages, or citation content that runs JavaScript in viewers' browsers, enabling in-app phishing, or session hijacking where iframeSandboxAllowSameOrigin is enabled.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 5.1 Medium | CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N | VulnCheck |
| 3.1 | 4.6 Medium | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N | VulnCheck |
Weaknesses
- CWE-79 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Products
| Product | Versions |
|---|---|
open-webuiopen-webui |
|
References
- GitHub Security Advisory (GHSA-9wj4-mcm3-ppj6)vendor-advisory
- VulnCheck Advisory: Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embedsthird-party-advisory
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