CVE-2026-44557: Open webui Open WebUI Vulnerable To Global Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6c2x-gcp3-gp73",
  "modified" : "2026-05-15T23:52:57Z",
  "published" : "2026-05-08T19:51:33Z",
  "aliases" : [ "CVE-2026-44557" ],
  "summary" : "Open WebUI vulnerable to Global Knowledge Base Enumeration via knowledge-bases Meta-Collection",
  "details" : "# Global Knowledge Base Enumeration via knowledge-bases Meta-Collection\n\n## Affected Component\n\nRetrieval collection access validation:\n- `backend/open_webui/routers/retrieval.py` (lines 2330-2355, `_validate_collection_access`)\n- `backend/open_webui/routers/retrieval.py` (query endpoints, e.g. `POST /query/doc`)\n\n## Affected Versions\n\nCurrent main branch (commit `6fdd19bf1`) and likely all versions with the knowledge base subsystem.\n\n## Description\n\nThe `_validate_collection_access` function uses an incomplete allowlist that only enforces ownership checks for collections matching `user-memory-*` and `file-*` patterns. All other collection names pass through unchecked — including the system-level `knowledge-bases` meta-collection, which stores the IDs, names, and descriptions of every knowledge base on the instance.\n\nAny authenticated user can query this meta-collection directly via the retrieval query endpoints to obtain a global index of all knowledge bases across all users.\n\n```python\n# retrieval.py:2330-2355 — incomplete collection allowlist\ndef _validate_collection_access(user, collection_name, ...):\n    if collection_name.startswith('user-memory-'):\n        # Check user-memory ownership\n        ...\n    elif collection_name.startswith('file-'):\n        # Check file access\n        ...\n    # Everything else (including \"knowledge-bases\") passes through unchecked\n```\n\nThis finding is the enabler for the KB destruction (`process/web`), KB content injection (`process/file`), and RAG vector search access bypass findings — all of which require knowing a target KB's UUID. Without this enumeration, UUIDs are random and practically unguessable; with it, UUIDs across the entire instance are trivially obtained.\n\n## CVSS 3.1 Breakdown\n\n| Metric | Value | Rationale |\n|--------|-------|-----------|\n| Attack Vector | Network (N) | Exploited remotely via API call |\n| Attack Complexity | Low (L) | Single API call |\n| Privileges Required | Low (L) | Requires any authenticated user account |\n| User Interaction | None (N) | No victim interaction required |\n| Scope | Unchanged (U) | Impact within the knowledge base boundary |\n| Confidentiality | Low (L) | Discloses KB metadata (IDs, names, descriptions) across all users |\n| Integrity | None (N) | No direct data modification |\n| Availability | None (N) | No denial of service |\n\n## Attack Scenario\n\n1. Attacker (any authenticated user) sends:\n   ```\n   POST /api/v1/retrieval/query/doc\n   {\n     \"collection_name\": \"knowledge-bases\",\n     \"query\": \"confidential\"\n   }\n   ```\n2. `_validate_collection_access` does not recognize the `knowledge-bases` prefix and lets the request pass.\n3. The vector search returns the most relevant documents from the meta-collection — knowledge base records including their UUIDs, names, and descriptions — across all users on the instance.\n4. Attacker varies the query to enumerate more KBs: `\"project\"`, `\"internal\"`, `\"private\"`, etc.\n5. Attacker now has a full target list for subsequent attacks (destruction, poisoning, content extraction).\n\n## Impact\n\n- **Information disclosure:** KB names and descriptions may reveal sensitive project names, internal initiatives, or user activities\n- **Enabler for other attacks:** Unlocks the following findings by supplying the required target UUIDs:\n  - KB destruction/poisoning via `process/web`\n  - Cross-user content injection via `process/file`\n  - RAG vector search access bypass in `retrieval/utils.py`\n- Transforms these from theoretical (requires UUID guessing) to trivially exploitable (UUIDs enumerable)\n\n## Preconditions\n\n- Attacker must have a valid user account",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "open-webui"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.9.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.8.12"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/open-webui/open-webui/security/advisories/GHSA-6c2x-gcp3-gp73"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44557"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/open-webui/open-webui"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-200", "CWE-862", "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-08T19:51:33Z",
    "nvd_published_at" : "2026-05-15T20:16:47Z"
  }
}