CVE-2026-45350
HighSummary
In Open WebUI prior to version 0.8.6, there is a vulnerability in the chat completion API that allows attackers to bypass tool restrictions, potentially enabling unauthorized actions or access.
Risk Assessment
The organization may be exposed to unauthorized use of server tools, which could lead to serious security implications.
Recommendation
It is recommended to upgrade to version 0.8.6 or later to mitigate this vulnerability and implement additional access controls for the API.
Other vulnerabilities in Open WebUI
See all- CVE-2026-88002Medium
Open WebUI from 0.5.0 to 0.11.1 has a vulnerability causing infinite loop in the message-chain reconstruction helper in backend/open_webui/utils/misc.py. An authenticated user can store id-less messages in a cyclic structure, blocking the event loop and growing memory until termination. Fixed in 0.11.1.
- CVE-2026-88001Medium
Open WebUI from 0.9.5 to 0.11.1 fails to reapply WEB_FETCH_FILTER_LIST or private-address controls to HTTP redirect destinations when AIOHTTP_CLIENT_ALLOW_REDIRECTS is enabled. An authenticated user can redirect fetches to excluded hosts, loopback, private networks, or cloud metadata services, and route content into various features. Fixed in 0.11.1.
- CVE-2026-88000Medium
Open WebUI from 0.10.0 to 0.11.1 has an infinite loop vulnerability in the chat deletion helper in backend/open_webui/models/chats.py. An authenticated user can create a cyclic chat tree and delete a message, causing a synchronous infinite loop that blocks all user requests until process termination. Fixed in 0.11.1.
- CVE-2026-87999High
Open WebUI prior to 0.11.1 in POST /api/v1/retrieval/process/web and POST /api/v1/retrieval/process/web/search treated Python's globally routable address classification as proof that a destination was external. An authenticated user could make an Azure-hosted instance fetch and return content from 168.63.129.16, the Azure platform channel, as well as other reserved ranges that the standard classification did not reject.
- CVE-2026-87998High
Open WebUI from 0.10.0 until 0.11.1 in DELETE /api/v1/knowledge/{id}/delete authorized deletion against the knowledge base but then removed its administrator-owned external connection without a separate administrator check or a check for other dependent knowledge bases. A non-administrator with write access to one external knowledge base could delete shared instance configuration and make every other knowledge base using that connection unavailable.
- CVE-2026-87997Medium
Open WebUI from 0.10.0 to 0.11.1 fails to apply folder write-access checks when creating a new chat with a client-supplied folder_id in POST /api/chat/completions and POST /api/v1/chat/completions. An authenticated user who knows a shared folder identifier can inject a chat into a folder where they have read-only or no write access, causing the entry to appear to authorized readers. Fixed in 0.11.1.
- CVE-2026-87996High
Open WebUI from 0.9.6 until 0.11.1 in SafePlaywrightURLLoader in backend/open_webui/retrieval/web/utils.py validated a user-controlled hostname in Python and then let the Playwright browser resolve it again in the sync and async request interceptors. An authenticated user controlling authoritative DNS could return a public address to validation and an internal address to the browser, exposing responses from internal services or cloud metadata through web search or URL ingestion.
- CVE-2026-87995High
Open WebUI from 0.8.11 until 0.11.1 in src/lib/components/chat/FileNav/PortPreview.svelte rendered terminal port content in an iframe sandbox containing both allow-scripts and allow-same-origin. Because the terminal proxy serves that content from the Open WebUI origin, an authenticated user with access to a shared terminal server could host script on a previewed port and take over a victim's account when the victim opened the preview.
- CVE-2026-87994Medium
Open WebUI from 0.9.5 to 0.11.1 does not verify that the calling user authored the targeted message in the channel branch of chat_completion. A channel member can replace another member's message while preserving the victim as the stored author, altering the conversation record without gaining access to other channels. Fixed in 0.11.1.
- CVE-2026-87017Medium
Open WebUI from 0.7.0 to 0.11.1 fails to apply metadata filter in the built-in knowledge search tool, allowing an authenticated user to enumerate identifiers, names, and descriptions of inaccessible knowledge bases from the shared collection. Document text remains separate, but metadata is exposed. Fixed in 0.11.1.
Original NVD description (English source)
Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline. Prior to 0.8.6, there is a vulnerability in chat completion API, which allows attackers to bypass tool restrictions, potentially enabling unauthorized actions or access. In the chat_completion API, the parameters tool_ids and tool_servers are supplied by the user. These parameters are used to create a tools_dict by the middleware. This is then used by get_tool_by_id to retrieve the appropriate tool. However, there is no checks in that ensures the user that uses the API has permission to use the tool, meaning that a user can invoke any server tool by supplying the correct tool_id or tool_servers parameters via the chat completion API. Moreover, the authentication token stored in the server would be used when invoking the tool, so the tool will be invoked with the server privilege. This vulnerability is fixed in 0.8.6.

