Open WebUI: Arena task endpoints can bypass underlying model access controls

{
  "id": "a9aa2a656be9c3ff33c04e24fecc3a6b946e8c1793dcc832d20a888bf59ec606",
  "url": "https://osv.dev/vulnerability/CVE-2026-59225",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Open WebUI: Arena task endpoints can bypass underlying model access controls",
    "summary": "Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.12 before 0.10.0, an authenticated non-admin user with read access to an arena wrapper model can reach a restricted underlying model through task endpoints such as /api/v1/tasks/moa/completions. The normal chat route resolves arena models before the final chat dispatch and therefore re-checks the selected underlying model. The task routes call utils.chat.generate_chat_completion() directly. In that direct path, arena fallback resolution happens after the wrapper access check and then recurses with bypass_filter=True, skipping the selected submodel's access check. This issue is fixed in version 0.10.0.",
    "evidence": "osv:CVE-2026-59225",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-59225",
      "aliases": [
        "CVE-2026-59225",
        "GHSA-m3qf-58wf-w979",
        "PYSEC-2026-3601"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/open-webui/open-webui",
              "type": "GIT",
              "events": [
                {
                  "introduced": "9bd84258d09eefe7bf975878fb0e31a5dadfe0f8"
                },
                {
                  "fixed": "4d2e13cf2bcc451b33bb6374bea4d2163e6cc94c"
                },
                {
                  "fixed": "dc4924b66e655b315e3be4430a3e51b7d5c20acc"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:openwebui:open_webui:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0.8.12"
                      },
                      {
                        "fixed": "0.10.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "dc4924b66e655b315e3be4430a3e51b7d5c20acc"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "4d2e13cf2bcc451b33bb6374bea4d2163e6cc94c"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v0.10.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.9.5",
            "v0.9.4",
            "v0.9.3",
            "v0.9.2",
            "v0.9.1",
            "v0.9.0",
            "v0.8.12"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-59225.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:50.179530535Z",
      "provider": "osv",
      "references": [
        "https://github.com/open-webui/open-webui/releases/tag/v0.10.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59225.json",
        "https://github.com/open-webui/open-webui/security/advisories/GHSA-m3qf-58wf-w979",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-59225",
        "https://github.com/open-webui/open-webui/commit/dc4924b66e655b315e3be4430a3e51b7d5c20acc",
        "https://github.com/open-webui/open-webui/pull/26046"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-862"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59225.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-59225",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 518300,
  "published_at": "2026-07-09T17:12:14.141+00:00"
}