{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "extracted_events": [
              {
                "introduced": "0.9.0"
              },
              {
                "fixed": "0.11.1"
              }
            ],
            "source": [
              "AFFECTED_FIELD",
              "REFERENCES"
            ]
          },
          "events": [
            {
              "introduced": "f31768e20e5c6b4f6da0ef657877298b359936cf"
            },
            {
              "fixed": "aeda6ff13a25d3b3ba1b303609f35382db22142c"
            },
            {
              "fixed": "d3e8bf3405e848cfba377814d0aa7ba7290e414d"
            }
          ],
          "repo": "https://github.com/open-webui/open-webui",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-3g9q-v48f-hh9w"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-405",
      "CWE-770"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/87xxx/CVE-2026-87011.json"
  },
  "details": "Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.1, the unauthenticated POST /oauth/backchannel-logout handler in backend/open_webui/utils/oauth.py fetched the OIDC discovery document and signing keys before validating a submitted logout token. Each request repeated uncached network fetches, and the signing-key lookup blocked the async event loop, so requests carrying invalid tokens could stall the single-worker instance and amplify traffic to the identity provider when ENABLE_OAUTH_BACKCHANNEL_LOGOUT was enabled. This issue is fixed in version 0.11.1.",
  "id": "CVE-2026-87011",
  "modified": "2026-09-15T03:31:05.296800146Z",
  "published": "2026-09-09T20:54:26.207Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/open-webui/open-webui/releases/tag/v0.11.1"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/87xxx/CVE-2026-87011.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/open-webui/open-webui/security/advisories/GHSA-3g9q-v48f-hh9w"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-87011"
    },
    {
      "type": "FIX",
      "url": "https://github.com/open-webui/open-webui/commit/aeda6ff13a25d3b3ba1b303609f35382db22142c"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Open WebUI: Unauthenticated requests can stall the server via uncached OIDC fetches in back-channel logout"
}