Security Vulnerabilities
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the type: "file" (non-full-context), type: "text" with collection_name, and bare collection_name/collection_names paths in the get_sources_from_items function perform vector store queries without any authorization check, allowing users to extract content from files and knowledge bases they do not have access to. This vulnerability is fixed in 0.9.0.
CVSS Score
6.5
EPSS Score
0.0
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the is_user_channel_member function checks whether a ChannelMember row exists but does not check the is_active field. When a user is deactivated from a group or DM channel (removed by the channel owner, or leaves voluntarily), their membership row persists with is_active=False and status='left'. Because the authorization check ignores this field, the deactivated user retains full read and write access to the channel via direct API calls. This vulnerability is fixed in 0.9.0.
CVSS Score
5.4
EPSS Score
0.0
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the POST /api/v1/models/import endpoint allows users with the workspace.models_import permission to overwrite any existing model in the database, regardless of ownership. When an imported model's ID matches an existing model, the endpoint merges the attacker's payload over the existing model data and writes it to the database with no ownership or access grant validation. Additionally, filter_allowed_access_grants is never called, bypassing the access grant restrictions enforced on all other model mutation endpoints. This vulnerability is fixed in 0.9.0.
CVSS Score
6.5
EPSS Score
0.0
Published
2026-05-15
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.
CVSS Score
5.0
EPSS Score
0.0
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the LDAP authentication endpoint does not validate that the submitted password is non-empty before performing a Simple Bind against the LDAP server. The LdapForm Pydantic model accepts password: str with no minimum length constraint, so an empty string passes validation. The subsequent Connection.bind() call succeeds on vulnerable LDAP servers, and the application issues a full session token for the target user. This vulnerability is fixed in 0.9.0.
CVSS Score
9.1
EPSS Score
0.026
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the tool_servers and terminal_servers keys in utils/tools.py do use a prefix. When two or more Open WebUI instances share a Redis database (a supported and documented deployment pattern, e.g., for multi-region deployments, blue-green setups, or cluster topologies), the unprefixed keys collide. An admin on Instance A writing to tool_servers overwrites the value read by Instance B — causing Instance B's users to receive Instance A's tool server configuration. This vulnerability is fixed in 0.9.0.
CVSS Score
8.7
EPSS Score
0.0
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, administrative role changes and user deletions do not iterate SESSION_POOL to disconnect affected sessions. As a result, a user whose admin role has been revoked retains admin privileges within their existing Socket.IO session for as long as they keep the connection alive (via automatic heartbeats). The gap is exclusive to the Socket.IO session cache. This vulnerability is fixed in 0.9.0.
CVSS Score
8.1
EPSS Score
0.0
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, the POST /api/v1/retrieval/process/web endpoint accepts a user-supplied collection_name and an overwrite query parameter (default: True). It performs no authorization check on whether the calling user owns or has write access to the target collection. When overwrite=True, save_docs_to_vector_db calls VECTOR_DB_CLIENT.delete_collection() on the target collection before writing new content. This vulnerability is fixed in 0.9.0.
CVSS Score
8.1
EPSS Score
0.0
Published
2026-05-15
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.9.0, Open WebUI supports model composition via base_model_id: a user-defined model (e.g., "Cheap Assistant") can reference an existing base model (e.g., "gpt-4-turbo-restricted") that provides the actual inference capability. When a user queries the composed model, the access control pipeline verifies the user has access to the composed model but never re-verifies access to the chained base model. Additionally, the model creation and import endpoints accept arbitrary base_model_id values without checking that the caller has access to that base model. Combined, this allows any user with the default model creation permission to create a model that chains to a restricted base model — and then invoke it, causing the server to dispatch the request to the restricted base model using the admin-configured API key. This vulnerability is fixed in 0.9.0.
CVSS Score
7.6
EPSS Score
0.0
Published
2026-05-15
Missing bounds validation in the MQTT v5.0 property parser in coreMQTT before 5.0.1 allows an MQTT broker to cause a denial of service by sending a crafted packet.
To remediate this issue, users should upgrade to v5.0.1.
CVSS Score
8.7
EPSS Score
0.0
Published
2026-05-15