{"id":"CVE-2026-45303","aliases":["GHSA-4vrc-m9ch-6m3r","PYSEC-2026-2704"],"url":"https://o3.security/vulnerability/CVE-2026-45303","summary":"Open WebUI: Stored XSS via the HTML renedering view","details":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.6.5, through the HTML rendering view, scripts can be injected and executed. The frontend provides a function to visualize the HTML content of a current chat. The content is embedded in an iFrame with the allow-scripts allow-forms allow-same-origin sandbox directive. This means that the content is placed in a sandbox but with permission to execute scripts and access the parent’s data (e.g., local storage). As a result, only a few functions are restricted (e.g., displaying an alert box), but in effect, the sandbox attribute is largely nullified. This vulnerability is fixed in 0.6.5.","published":"2026-05-15T21:21:43Z","modified":"2026-08-12T03:51:25.872218393Z","cvss":{"score":7.7,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N"},"epss":{"score":0.00225,"percentile":0.13243,"asOf":"2026-08-10"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"open-webui","fixedVersion":"0.6.5"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45303.json"},{"type":"ADVISORY","url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-4vrc-m9ch-6m3r"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-45303"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:25.872218393Z"}}