CVE-2026-109291: Open WebUI 0.6.33 before 0.11.4 Stored XSS via Citation embed_url

Severity: high (CVSS 7.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-12 · updated 2026-10-18
Weakness: CWE-79

Description

Open WebUI from 0.6.33 before 0.11.4 contains a cross-site scripting vulnerability that allows authenticated users to execute script in victims' sessions by storing javascript: URLs in citation embed_url fields. Attackers can share a crafted chat whose citation, when clicked, is passed to window.open, letting them steal localStorage.token and act as the victim.

Affected products

open-webui: from 0.6.33 before 0.11.4 — fixed in 0.11.4

How to fix

Upgrade to a fixed version: open-webui 0.11.4. Check the vendor advisory for mitigations.

References

https://github.com/open-webui/open-webui/security/advisories/GHSA-qpqv-xwg8-cqpj
https://www.vulncheck.com/advisories/open-webui-0.6.33-before-0.11.4-stored-xss-via-citation-embed-url

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