{"id":"CVE-2026-109300","published":"2026-10-12T17:17:23.700","lastModified":"2026-10-15T15:55:45.630","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.","cvssScore":4.6,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N","cwes":["CWE-79"],"vendors":[],"products":[],"references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6","tags":[]},{"url":"https://www.vulncheck.com/advisories/open-webui-0.6.31-before-0.11.4-stored-xss-via-tool-call-embeds","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6","tags":[]}],"exploitRefs":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6","tags":[]},{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6","tags":[]}],"hasPoc":true,"ai":null}