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.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.5.11, there is a blind server side request forgery (SSRF) via the PDF generate function. In the PDF export, user inputs are interpreted as HTML and embedded into the PDF. According to tests, scripts and some potentially dangerous tags (iFrame, Object, etc.) are blocked, preventing server-side content from being read through this vulnerability. However, an image tag can be used to force a server-side request (SSRF), as shown in the following below. This vulnerability is fixed in 0.5.11.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.6.10, when uploading an audio file, the name of the file is derived from the original HTTP upload request and is not validated or sanitized. This allows for users to upload files with names containing dot-segments in the file path and traverse out of the intended uploads directory. Effectively, users can upload files anywhere on the filesystem the user running the web server has permission. This vulnerability is fixed in 0.6.10.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.12, the /api/v1/utils/code/execute endpoint executes arbitrary Python code via Jupyter for any verified user, even when the admin has set ENABLE_CODE_EXECUTION=false. The feature gate is not enforced on the API endpoint — the configuration says "disabled" but code still executes. This vulnerability is fixed in 0.8.12.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.0, a Stored Cross-Site Scripting (XSS) vulnerability exists in the Banner component due to an improper sanitization order (specifically, DOMPurify is executed before the marked library). This vulnerability allows a compromised or malicious administrator to plant a malicious payload in the global banner. Crucially, this vector enables Privilege Escalation, as the malicious banner is rendered for all users, including the Super Admin (Primary Admin). Consequently, the payload successfully bypasses the existing security mechanism. An attacker can leverage this to steal the Super Admin's session token This vulnerability is fixed in 0.8.0.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.0, Excel file attachments are previewed in an unsafe way. A crafted XLSX file payload can be used to cause the sheetjs function sheet_to_html to embed an XSS payload into the generated HTML. This is subsequently added to the DOM unsanitized via @html causing the payload to trigger. This vulnerability is fixed in 0.8.0.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.1.124, when attaching files to a promp, the name of the file is derived from the original HTTP upload request and is not validated or sanitized. This allows for users to upload files with names containing dot-segments in the file path and traverse out of the intended uploads directory. Effectively, users can upload files anywhere on the filesystem the user running the web server has permission. This vulnerability is fixed in 0.1.124.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.11, the API /api/v1/notes/{note_id} endpoint lacks proper authorization checks, allowing authenticated users to retrieve notes belonging to other users by guessing or enumerating UUIDs. This results in unauthorized disclosure of potentially sensitive or private user data. This vulnerability is fixed in 0.8.11.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.0, GET /api/v1/memories/ef is accessible without authentication and executes request.app.state.EMBEDDING_FUNCTION(...). This allows any unauthenticated caller to trigger embedding generation which can lead to direct cost exposure if a paid provider is used. This vulnerability is fixed in 0.8.0.

Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Versions 0.7.2 and below contain a Blind Server Side Request Forgery in the functionality that allows editing an image via a prompt. The affected function performs a GET request to a user-provided URL with no restriction on the domain, allowing the local address space to be accessed. Since the SSRF is blind (the response cannot be read), the primary impact is port scanning of the local network, as whether a port is open can be determined based on whether the GET request succeeds or fails. These response differentials can be automated to iterate through the entire port range and identify open ports. If the service running on an open port can be inferred, an attacker may be able to interact with it in a meaningful way, provided the service offers state-changing GET request endpoints. This issue was unresolved at the time of publication.