{"id":"CVE-2026-44550","aliases":["EUVD-2026-30603","GHSA-hr43-rjmr-7wmm","PYSEC-2026-2735"],"status":"published","title":"Open WebUI: Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts","description":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, FolderForm uses model_config = ConfigDict(extra='allow'), which permits arbitrary fields to pass through Pydantic validation and be included in model_dump(exclude_unset=True). In insert_new_folder, the server-assigned user_id is placed at the start of the dict and then overwritten by the spread of form data. Because FolderModel declares user_id: str as a real field (not just a form extra), any attacker-supplied user_id in the POST body is accepted by the model and persisted on the Folder row. This vulnerability is fixed in 0.9.0.","severity":{"version":"3.1","score":5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00287,"percentile":0.21446,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-862"],"published":"2026-05-08T19:38:54Z","modified":"2026-10-28T02:30:44Z","fixes":[{"ecosystem":"PyPI","package":"open-webui","fixed_in":["0.9.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"open-webui","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"0.8.12"},{"fixed":"0.9.0"}]}]},{"source":"osv","ecosystem":"PyPI","package":"open-webui","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.0"}]}],"versions":["0.1.124","0.1.125","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.3.1","0.3.10","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.17.dev2","0.3.17.dev3","0.3.17.dev4","0.3.17.dev5","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26","0.3.27","0.3.27.dev1","0.3.27.dev2","0.3.27.dev3","0.3.28","0.3.29","0.3.3","0.3.30","0.3.30.dev1","0.3.30.dev2","0.3.31","0.3.31.dev1","0.3.32","0.3.33","0.3.33.dev1","0.3.34","0.3.35","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.0.dev1","0.4.0.dev2","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.4.6.dev1","0.4.7","0.4.8","0.5.0","0.5.0.dev1","0.5.0.dev2","0.5.1","0.5.10","0.5.11","0.5.12","0.5.13","0.5.14","0.5.15","0.5.16","0.5.17","0.5.18","0.5.19","0.5.2","0.5.20","0.5.3","0.5.3.dev1","0.5.4","0.5.5","0.5.6","0.5.7","0.5.8","0.5.9","0.6.0","0.6.1","0.6.10","0.6.11","0.6.12","0.6.13","0.6.14","0.6.15","0.6.16","0.6.18","0.6.19","0.6.2","0.6.20","0.6.21","0.6.22","0.6.23","0.6.24","0.6.25","0.6.26","0.6.26.dev1","0.6.27","0.6.28","0.6.29","0.6.3","0.6.30","0.6.31","0.6.32","0.6.33","0.6.34","0.6.35","0.6.36","0.6.37","0.6.38","0.6.39","0.6.4","0.6.40","0.6.41","0.6.42","0.6.43","0.6.5","0.6.6","0.6.6.dev1","0.6.7","0.6.8","0.6.9","0.7.0","0.7.1","0.7.2","0.8.0","0.8.1","0.8.10","0.8.11","0.8.12","0.8.2","0.8.3","0.8.4","0.8.5","0.8.6","0.8.7","0.8.8","0.8.9"]},{"source":"osv","ecosystem":"PyPI","package":"open-webui","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0.9.0"}]}],"versions":["0.1.124","0.1.125","0.2.0","0.2.1","0.2.2","0.2.3","0.2.4","0.2.5","0.3.0","0.3.1","0.3.10","0.3.12","0.3.13","0.3.14","0.3.15","0.3.16","0.3.17","0.3.17.dev2","0.3.17.dev3","0.3.17.dev4","0.3.17.dev5","0.3.18","0.3.19","0.3.2","0.3.20","0.3.21","0.3.22","0.3.23","0.3.24","0.3.25","0.3.26","0.3.27","0.3.27.dev1","0.3.27.dev2","0.3.27.dev3","0.3.28","0.3.29","0.3.3","0.3.30","0.3.30.dev1","0.3.30.dev2","0.3.31","0.3.31.dev1","0.3.32","0.3.33","0.3.33.dev1","0.3.34","0.3.35","0.3.4","0.3.5","0.3.6","0.3.7","0.3.8","0.3.9","0.4.0","0.4.0.dev1","0.4.0.dev2","0.4.1","0.4.2","0.4.3","0.4.4","0.4.5","0.4.6","0.4.6.dev1","0.4.7","0.4.8","0.5.0","0.5.0.dev1","0.5.0.dev2","0.5.1","0.5.10","0.5.11","0.5.12","0.5.13","0.5.14","0.5.15","0.5.16","0.5.17","0.5.18","0.5.19","0.5.2","0.5.20","0.5.3","0.5.3.dev1","0.5.4","0.5.5","0.5.6","0.5.7","0.5.8","0.5.9","0.6.0","0.6.1","0.6.10","0.6.11","0.6.12","0.6.13","0.6.14","0.6.15","0.6.16","0.6.18","0.6.19","0.6.2","0.6.20","0.6.21","0.6.22","0.6.23","0.6.24","0.6.25","0.6.26","0.6.26.dev1","0.6.27","0.6.28","0.6.29","0.6.3","0.6.30","0.6.31","0.6.32","0.6.33","0.6.34","0.6.35","0.6.36","0.6.37","0.6.38","0.6.39","0.6.4","0.6.40","0.6.41","0.6.42","0.6.43","0.6.5","0.6.6","0.6.6.dev1","0.6.7","0.6.8","0.6.9","0.7.0","0.7.1","0.7.2","0.8.0","0.8.1","0.8.10","0.8.11","0.8.12","0.8.2","0.8.3","0.8.4","0.8.5","0.8.6","0.8.7","0.8.8","0.8.9"]}],"products":[{"vendor":"open-webui","product":"open-webui"},{"vendor":"openwebui","product":"open_webui"}],"references":[{"url":"https://github.com/open-webui/open-webui/security/advisories/GHSA-hr43-rjmr-7wmm","tags":["x_refsource_CONFIRM","Exploit","Mitigation","Vendor Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-44550","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-hr43-rjmr-7wmm","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/44xxx/CVE-2026-44550.json","tags":["advisory"]},{"url":"https://github.com/open-webui/open-webui","tags":["package"]},{"url":"https://pypi.org/project/open-webui","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-44550","title":"Open WebUI: Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts","description":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, FolderForm uses model_config = ConfigDict(extra='allow'), which permits arbitrary fields to pass through Pydantic validation and be included in model_dump(exclude_unset=True). In insert_new_folder, the server-assigned user_id is placed at the start of the dict and then overwritten by the spread of form data. Because FolderModel declares user_id: str as a real field (not just a form extra), any attacker-supplied user_id in the POST body is accepted by the model and persisted on the Folder row. This vulnerability is fixed in 0.9.0.","status":"published","published":"2026-05-15T20:00:59.583Z","modified":"2026-05-15T22:21:43.34Z","cvss":[{"version":"3.1","score":5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T13:43:00.288193Z"}],"euvd":[{"id":"EUVD-2026-30603","description":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, FolderForm uses model_config = ConfigDict(extra='allow'), which permits arbitrary fields to pass through Pydantic validation and be included in model_dump(exclude_unset=True). In insert_new_folder, the server-assigned user_id is placed at the start of the dict and then overwritten by the spread of form data. Because FolderModel declares user_id: str as a real field (not just a form extra), any attacker-supplied user_id in the POST body is accepted by the model and persisted on the Folder row. This vulnerability is fixed in 0.9.0.","status":"published","published":"2026-05-15T20:00:59Z","modified":"2026-05-15T22:21:43Z","cvss":[{"version":"3.1","score":5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T19:04:28.290329Z"}],"ghsa":[{"id":"GHSA-hr43-rjmr-7wmm","title":"Open WebUI's Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts","description":"# Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts\n\n## Affected Component\n\nFolder creation endpoint and form model:\n- `backend/open_webui/models/folders.py` (lines 72-77, `FolderForm` with `extra='allow'`)\n- `backend/open_webui/models/folders.py` (lines 95-106, `insert_new_folder` dict construction)\n- `backend/open_webui/routers/folders.py` (line 119, `create_folder` endpoint)\n\n## Affected Versions\n\nCurrent main branch (commit `6fdd19bf1`) and likely all versions since `FolderForm` adopted `extra='allow'`.\n\n## Description\n\n`FolderForm` uses `model_config = ConfigDict(extra='allow')`, which permits arbitrary fields to pass through Pydantic validation and be included in `model_dump(exclude_unset=True)`. In `insert_new_folder`, the server-assigned `user_id` is placed at the start of the dict and then overwritten by the spread of form data:\n\n```python\n# models/folders.py:95-106\nfolder = FolderModel(\n    **{\n        'id': id,                                              # server\n        'user_id': user_id,                                    # server — overwritten below\n        **(form_data.model_dump(exclude_unset=True) or {}),    # user-controlled (extra='allow')\n        'parent_id': parent_id,\n        'created_at': int(time.time()),\n        'updated_at': int(time.time()),\n    }\n)\n```\n\nBecause `FolderModel` declares `user_id: str` as a real field (not just a form extra), any attacker-supplied `user_id` in the POST body is accepted by the model and persisted on the `Folder` row.\n\n## Attack Scenario\n\n1. Attacker discovers a victim's user ID. User UUIDs commonly leak via the user search endpoint (`GET /api/v1/users/search`, intentionally accessible to verified users for sharing UI), shared chat metadata, or channel member lists.\n2. Attacker sends:\n   ```\n   POST /api/v1/folders/\n   {\n     \"name\": \"Important: Click here\",\n     \"user_id\": \"\u003cvictim_user_id\u003e\",\n     \"meta\": {\"icon\": \"warning\"},\n     \"data\": {...}\n   }\n   ```\n3. Pydantic accepts the extra `user_id` field (allowed by `extra='allow'`).\n4. `insert_new_folder` spreads the form data over the server-set `'user_id': user_id`, overwriting it with the attacker's value.\n5. The `Folder` row is persisted with `user_id = \u003cvictim_user_id\u003e`.\n6. The victim sees the attacker-planted folder in their UI on next load because `GET /api/v1/folders/` filters by the viewer's own `user_id`.\n\nThe attacker can repeat this to plant multiple folders, use crafted `name` values for phishing (\"Click here to recover account\" / \"Security alert\"), and abuse the `meta` and `data` fields to add visual elements that further mimic legitimate content.\n\n## Impact\n\n- Unauthorized write into victim's folder tree\n- Phishing surface: attacker-controlled `name`, `meta`, and `data` render in the victim's UI in a trusted context\n- DoS / spam: attacker can flood a victim with arbitrary folders; victim must manually delete each one\n- Attacker cannot read the folder back — all read paths filter by the caller's own `user_id` — so confidentiality is preserved, but integrity and trust are compromised\n\n## Preconditions\n\n- Attacker must have an authenticated account with `features.folders` permission (default for all users)\n- Attacker must know or guess the victim's user UUID (obtainable through various non-sensitive endpoints)","status":"published","published":"2026-05-08T19:38:54Z","modified":"2026-05-15T23:52:19Z","cvss":[{"version":"3.1","score":5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T14:40:11.298154Z"}],"nvd":[{"id":"CVE-2026-44550","description":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, FolderForm uses model_config = ConfigDict(extra='allow'), which permits arbitrary fields to pass through Pydantic validation and be included in model_dump(exclude_unset=True). In insert_new_folder, the server-assigned user_id is placed at the start of the dict and then overwritten by the spread of form data. Because FolderModel declares user_id: str as a real field (not just a form extra), any attacker-supplied user_id in the POST body is accepted by the model and persisted on the Folder row. This vulnerability is fixed in 0.9.0.","status":"published","published":"2026-05-15T20:16:46.293Z","modified":"2026-06-17T10:50:46.533Z","cvss":[{"version":"3.1","score":5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"secondary"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T14:12:19.39893Z"}],"osv":[{"id":"CVE-2026-44550","title":"Open WebUI: Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts","description":"Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, FolderForm uses model_config = ConfigDict(extra='allow'), which permits arbitrary fields to pass through Pydantic validation and be included in model_dump(exclude_unset=True). In insert_new_folder, the server-assigned user_id is placed at the start of the dict and then overwritten by the spread of form data. Because FolderModel declares user_id: str as a real field (not just a form extra), any attacker-supplied user_id in the POST body is accepted by the model and persisted on the Folder row. This vulnerability is fixed in 0.9.0.","status":"published","published":"2026-05-15T20:00:59.583Z","modified":"2026-10-28T02:30:44.922396752Z","cvss":[{"version":"3.1","score":5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T15:45:05.172514Z"},{"id":"GHSA-hr43-rjmr-7wmm","title":"Open WebUI's Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts","description":"# Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts\n\n## Affected Component\n\nFolder creation endpoint and form model:\n- `backend/open_webui/models/folders.py` (lines 72-77, `FolderForm` with `extra='allow'`)\n- `backend/open_webui/models/folders.py` (lines 95-106, `insert_new_folder` dict construction)\n- `backend/open_webui/routers/folders.py` (line 119, `create_folder` endpoint)\n\n## Affected Versions\n\nCurrent main branch (commit `6fdd19bf1`) and likely all versions since `FolderForm` adopted `extra='allow'`.\n\n## Description\n\n`FolderForm` uses `model_config = ConfigDict(extra='allow')`, which permits arbitrary fields to pass through Pydantic validation and be included in `model_dump(exclude_unset=True)`. In `insert_new_folder`, the server-assigned `user_id` is placed at the start of the dict and then overwritten by the spread of form data:\n\n```python\n# models/folders.py:95-106\nfolder = FolderModel(\n    **{\n        'id': id,                                              # server\n        'user_id': user_id,                                    # server — overwritten below\n        **(form_data.model_dump(exclude_unset=True) or {}),    # user-controlled (extra='allow')\n        'parent_id': parent_id,\n        'created_at': int(time.time()),\n        'updated_at': int(time.time()),\n    }\n)\n```\n\nBecause `FolderModel` declares `user_id: str` as a real field (not just a form extra), any attacker-supplied `user_id` in the POST body is accepted by the model and persisted on the `Folder` row.\n\n## Attack Scenario\n\n1. Attacker discovers a victim's user ID. User UUIDs commonly leak via the user search endpoint (`GET /api/v1/users/search`, intentionally accessible to verified users for sharing UI), shared chat metadata, or channel member lists.\n2. Attacker sends:\n   ```\n   POST /api/v1/folders/\n   {\n     \"name\": \"Important: Click here\",\n     \"user_id\": \"\u003cvictim_user_id\u003e\",\n     \"meta\": {\"icon\": \"warning\"},\n     \"data\": {...}\n   }\n   ```\n3. Pydantic accepts the extra `user_id` field (allowed by `extra='allow'`).\n4. `insert_new_folder` spreads the form data over the server-set `'user_id': user_id`, overwriting it with the attacker's value.\n5. The `Folder` row is persisted with `user_id = \u003cvictim_user_id\u003e`.\n6. The victim sees the attacker-planted folder in their UI on next load because `GET /api/v1/folders/` filters by the viewer's own `user_id`.\n\nThe attacker can repeat this to plant multiple folders, use crafted `name` values for phishing (\"Click here to recover account\" / \"Security alert\"), and abuse the `meta` and `data` fields to add visual elements that further mimic legitimate content.\n\n## Impact\n\n- Unauthorized write into victim's folder tree\n- Phishing surface: attacker-controlled `name`, `meta`, and `data` render in the victim's UI in a trusted context\n- DoS / spam: attacker can flood a victim with arbitrary folders; victim must manually delete each one\n- Attacker cannot read the folder back — all read paths filter by the caller's own `user_id` — so confidentiality is preserved, but integrity and trust are compromised\n\n## Preconditions\n\n- Attacker must have an authenticated account with `features.folders` permission (default for all users)\n- Attacker must know or guess the victim's user UUID (obtainable through various non-sensitive endpoints)","status":"published","published":"2026-05-08T19:38:54Z","modified":"2026-07-13T16:43:10.013558309Z","cvss":[{"version":"3.1","score":5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"cwes":["CWE-862"],"updated_at":"2026-11-02T15:46:49.621585Z"},{"id":"PYSEC-2026-2735","title":"Open WebUI's Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts","description":"# Mass Assignment via Pydantic extra='allow' Allows Creating Folders in Other Users' Accounts\n\n## Affected Component\n\nFolder creation endpoint and form model:\n- `backend/open_webui/models/folders.py` (lines 72-77, `FolderForm` with `extra='allow'`)\n- `backend/open_webui/models/folders.py` (lines 95-106, `insert_new_folder` dict construction)\n- `backend/open_webui/routers/folders.py` (line 119, `create_folder` endpoint)\n\n## Affected Versions\n\nCurrent main branch (commit `6fdd19bf1`) and likely all versions since `FolderForm` adopted `extra='allow'`.\n\n## Description\n\n`FolderForm` uses `model_config = ConfigDict(extra='allow')`, which permits arbitrary fields to pass through Pydantic validation and be included in `model_dump(exclude_unset=True)`. In `insert_new_folder`, the server-assigned `user_id` is placed at the start of the dict and then overwritten by the spread of form data:\n\n```python\n# models/folders.py:95-106\nfolder = FolderModel(\n    **{\n        'id': id,                                              # server\n        'user_id': user_id,                                    # server — overwritten below\n        **(form_data.model_dump(exclude_unset=True) or {}),    # user-controlled (extra='allow')\n        'parent_id': parent_id,\n        'created_at': int(time.time()),\n        'updated_at': int(time.time()),\n    }\n)\n```\n\nBecause `FolderModel` declares `user_id: str` as a real field (not just a form extra), any attacker-supplied `user_id` in the POST body is accepted by the model and persisted on the `Folder` row.\n\n## Attack Scenario\n\n1. Attacker discovers a victim's user ID. User UUIDs commonly leak via the user search endpoint (`GET /api/v1/users/search`, intentionally accessible to verified users for sharing UI), shared chat metadata, or channel member lists.\n2. Attacker sends:\n   ```\n   POST /api/v1/folders/\n   {\n     \"name\": \"Important: Click here\",\n     \"user_id\": \"\u003cvictim_user_id\u003e\",\n     \"meta\": {\"icon\": \"warning\"},\n     \"data\": {...}\n   }\n   ```\n3. Pydantic accepts the extra `user_id` field (allowed by `extra='allow'`).\n4. `insert_new_folder` spreads the form data over the server-set `'user_id': user_id`, overwriting it with the attacker's value.\n5. The `Folder` row is persisted with `user_id = \u003cvictim_user_id\u003e`.\n6. The victim sees the attacker-planted folder in their UI on next load because `GET /api/v1/folders/` filters by the viewer's own `user_id`.\n\nThe attacker can repeat this to plant multiple folders, use crafted `name` values for phishing (\"Click here to recover account\" / \"Security alert\"), and abuse the `meta` and `data` fields to add visual elements that further mimic legitimate content.\n\n## Impact\n\n- Unauthorized write into victim's folder tree\n- Phishing surface: attacker-controlled `name`, `meta`, and `data` render in the victim's UI in a trusted context\n- DoS / spam: attacker can flood a victim with arbitrary folders; victim must manually delete each one\n- Attacker cannot read the folder back — all read paths filter by the caller's own `user_id` — so confidentiality is preserved, but integrity and trust are compromised\n\n## Preconditions\n\n- Attacker must have an authenticated account with `features.folders` permission (default for all users)\n- Attacker must know or guess the victim's user UUID (obtainable through various non-sensitive endpoints)","status":"published","published":"2026-07-13T15:15:41.715716Z","modified":"2026-07-13T16:32:16.464585762Z","cvss":[{"version":"3.1","score":5,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:52:55.961245Z"}]}}