{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.6.31"
              },
              {
                "fixed": "0.11.4"
              }
            ],
            "source": "AFFECTED_FIELD"
          },
          "events": [
            {
              "introduced": "598282cf75de358215d045c617e70d28bc48929e"
            },
            {
              "fixed": "8bd8b4fac5e059578ac0c74b3c18d11139f88b7d"
            }
          ],
          "repo": "https://github.com/open-webui/open-webui",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-9wj4-mcm3-ppj6"
  ],
  "database_specific": {
    "cna_assigner": "VulnCheck",
    "cwe_ids": [
      "CWE-79"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109300.json"
  },
  "details": "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.",
  "id": "CVE-2026-109300",
  "modified": "2026-10-13T02:30:37.403676457Z",
  "published": "2026-10-12T16:04:58.200Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/109xxx/CVE-2026-109300.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-9wj4-mcm3-ppj6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-109300"
    },
    {
      "type": "ADVISORY",
      "url": "https://www.vulncheck.com/advisories/open-webui-0.6.31-before-0.11.4-stored-xss-via-tool-call-embeds"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Open WebUI 0.6.31 before 0.11.4 Stored XSS via Tool-Call Embeds"
}