XSS in Open-Webui
CVE-2026-109288
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.
Vulnerability class: XSS (Cross-Site Scripting)
Published .
CVSS v3 metric
CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:H/I:H/A:N.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/open-webui/open-webui/security/advisories/GHSA-wf9m-46cp-c6h6 (vendor-advisory)
- www.vulncheck.com/advisories/open-webui-before-0.11.4-stored-xss-via-javascript… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-109288?
- CVE-2026-109288 is a medium-severity vulnerability in Open-Webui, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2026-10-12.
- How severe is CVE-2026-109288?
- Medium severity. CVSS v3 base score is 6.4 out of 10.