CVE-2026-109288

MEDIUM 6.4

Open WebUI before 0.11.4 Stored XSS via javascript: URLs in Markdown Links

CVSS Score

6.4

EPSS Score

0.0%

EPSS Percentile

0th

Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into anchor hrefs without validating their scheme. Authenticated users can embed javascript: links in shared chats that, when clicked by a victim, steal the victim's JWT from local storage, including admins' tokens.

CWE	CWE-79
Vendor	open-webui
Product	open-webui
Published	Oct 12, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N

Attack Vector

Network

Attack Complexity

High

Privileges Required

Low

User Interaction

Required

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

None

Affected Versions

open-webui / open-webui

0 < 0.11.4

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/open-webui/open-webui/security/advisories/GHSA-wf9m-46cp-c6h6 vulncheck.com: https://www.vulncheck.com/advisories/open-webui-before-0.11.4-stored-xss-via-javascript-urls-in-markdown-links

Credits

🔍 r20z19 Classic298