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VULNERABILITIES

CVE-2026-109300 Details

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.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: [email protected]CVSS-B:4.6 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6 CISA-ADP
https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6 [email protected]
https://www.vulncheck.com/advisories/open-webui-0.6.31-before-0.11.4-stored-xss-via-tool-call-embeds [email protected]

Weakness Enumeration

CWE-IDCWE NameSource
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')[email protected]

Affected Products

No affected product data is available for this CVE.

Change History

2 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-109300
NVD Published Date:
Oct 12, 2026
NVD Last Modified:
Oct 15, 2026
Source:
[email protected]
CVE-2026-109300 Details - Not Deferred