Open WebUI: Any authenticated user can stall a worker via a knowledge-search pattern that backtracks catastrophically
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, the built-in knowledge search path in backend/open_webui/tools/knowledge_fs.py and backend/open_webui/tools/builtin.py let a chat participant choose a pattern used to grep knowledge files. Patterns containing regex metacharacters were compiled with Python's backtracking re engine and run against every line of every reachable file with no time limit, so a crafted pattern such as (x|x)*y and one matching uploaded file line can pin one CPU core and block the event loop. This causes availability impact for every other user of the affecte
Open WebUI: Stored XSS via unescaped KaTeX render-error fallback in rendered messages
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.10.0 until 0.11.0, src/lib/components/chat/Messages/Markdown/KatexRenderer.svelte could store and render a chat message whose math block makes KaTeX fail with a stack overflow instead of a parse error. The catch branch fell back to inserting the original math source into the page as HTML through {@html} rather than as text, so script in the message runs in the browser of whoever views it, including shared chats and channels. The viewer's session token in localStorage can be stolen, and an administrator viewer can have their account taken over. This is
Open WebUI: Tool source code disclosed to read-only users via the tool list and get endpoints
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. In 0.10.2 and earlier, the GET /api/v1/tools/, GET /api/v1/tools/list, and GET /api/v1/tools/id/{id} endpoints in backend/open_webui/routers/tools.py returned full Python tool source to authenticated non-admin read-only users. ToolResponse deliberately omitted source and specs, but ToolUserResponse permitted extra fields and handlers spread a full tool model dump into the response, re-admitting omitted fields. A non-admin with a read grant can obtain another user's server-side tool source, which commonly embeds hard-coded API keys, credentials, and internal
Open WebUI: Unapproved accounts can open terminal sessions via a WebSocket auth path missing the role check
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.8 until 0.11.0, the terminal WebSocket route in backend/open_webui/routers/terminals.py authenticated its own first-message JWT and never applied the verified-user role gate that get_verified_user enforces on HTTP terminal routes. An account whose role is pending, including a registered but unapproved account or an account deactivated back to pending, can open an interactive terminal session when at least one terminal server is configured and its access grants cover the account. This loses the account-approval boundary for terminal access while the
Open WebUI: Instance-wide stall via automation recurrence rules that force multi-second parsing
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, automation recurrence parsing in backend/open_webui/utils/automations.py anchored minutely and hourly rules at a fixed date of 2000-01-01 and then walked forward one interval at a time to find the next run. A single FREQ=MINUTELY rule enumerates roughly a quarter-century of occurrences synchronously on the event loop that also serves scheduler, HTTP, and WebSocket traffic, and the scheduler recomputes the next run for every claimed row on each poll. This causes availability impact for every other user of the instance. This issue is f
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. Prior to 0.11.0, Open WebUI resolved a hostname during URL validation and rejected private, loopback, and link-local addresses, but the HTTP clients resolved the hostname again at connection time. An authenticated attacker who controlled authoritative DNS for a submitted hostname could answer with a public address during validation and an internal one during connection, reaching cloud metadata, loopback admin APIs, or internal services through URL ingest, chat image_url fetches, image editing, or OAuth profile-picture fetches, with most paths returning the r
Open WebUI: Deletion of directories and file embeddings in other knowledge bases via sync cleanup
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, the sync cleanup endpoint authorized write access to the knowledge base in the URL but then acted on directory and file ids supplied in the request body without checking that those objects belonged to that knowledge base. A user with write access to one knowledge base could delete directories and remove file embeddings from another knowledge base, causing documents to drop out of retrieval results and breaking chat-with-file for targeted documents without disclosing contents. This issue is fixed in 0.11.0.
Open WebUI: Cross-user file content disclosure via request-scoped direct model knowledge metadata
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.8 until 0.11.0, inline direct model metadata accepted client-supplied knowledge attachments without filtering them against the caller's read access. Any authenticated user who knew another user's file id could have the builtin knowledge tools return indexed chunks from that file, causing a read-only cross-user confidentiality loss while leaving knowledge-base permissions and saved workspace model validation unaffected. This issue is fixed in 0.11.0.
Open WebUI: Same-origin XSS to account takeover via terminal file-preview iframe hardcoding allow-same-origin
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, the terminal file-preview serveUrl iframe branch always granted allow-same-origin together with allow-scripts for HTML files served from the application origin. Any authenticated user with access to a configured terminal server could cause script in a previewed file to run in the Open WebUI origin, read the victim's session token from localStorage, and take over the account, with possible server-side code execution if the victim was an admin or held workspace.functions. This issue is fixed in 0.11.0.
Open WebUI: Any authenticated user can reach internal services and cloud metadata via NAT64-encoded URLs
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.0 until 0.11.0, Open WebUI checked whether a user-supplied URL destination was globally routable by applying ipaddress.is_global to the literal IPv6 address without examining IPv4 addresses embedded in transition encodings. On a deployment with a NAT64 gateway, any verified user could wrap an internal or cloud-metadata IPv4 address in the NAT64 well-known prefix, pass the filter, and receive the internal response body through RAG URL ingestion, URL-to-markdown conversion, or web-search content retrieval. This issue is fixed in 0.11.0.
Open WebUI: Users denied the image-generation permission can still generate images via chat completions
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.7.0 until 0.11.0, the legacy chat-completions features block trusted a client-supplied image_generation flag and did not re-check the features.image_generation permission that the direct image routes and native function-calling path enforce. An authenticated user whose image-generation permission had been revoked could still consume the operator's configured image provider through chat completions, spending API credits and provider quota and writing generated files to operator storage, without exposing provider credentials or other users' data. This i
Open WebUI: Any authenticated user can cancel another user's chat generation via the chat delete endpoint
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, DELETE /api/v1/chats/{id} cancelled a chat's in-flight tasks before checking whether the caller could delete that chat. Any authenticated user who knew another user's chat id could abort that user's running model response, title generation, or tag generation, even though the delete was refused and no chat data was deleted, modified, or disclosed. This issue is fixed in 0.11.0.
Open WebUI: Account takeover via OAuth token exchange accepting tokens issued to any client
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.0 until 0.11.0, when ENABLE_OAUTH_TOKEN_EXCHANGE=True, /oauth/{provider}/token/exchange accepts a raw provider access token and validates it by calling the provider userinfo endpoint without confirming which OAuth client the token was issued to. Anyone holding an access token minted for any client registered with the same provider could exchange it for an Open WebUI session as that token user, including applications the operator does not control and has never authorized. This issue is fixed in 0.11.0.
Open WebUI: Any member with write access to a standard channel can edit or delete other members' messages
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.5.0 until 0.11.0, the standard channel message update and delete handlers accepted any caller holding write access on the channel without checking that the caller wrote the message. Because write access is the same grant a member needs to post, any ordinary participant in a shared standard channel could rewrite or permanently delete another participant message, while group and direct message handlers enforced authorship. This issue is fixed in 0.11.0.
Open WebUI: Client-side SSRF via unrestricted external resource loading in Vega/Vega-Lite chart rendering
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.6.34 until 0.11.0, Open WebUI renders vega and vega-lite fenced code blocks in chat content by building a Vega view in the viewer browser without a restricted resource loader. Any user who can place such a block where another user will see it can make that user browser issue attacker-chosen outbound GET requests and read responses from same-origin or CORS-permissive targets into the rendered page. This issue is fixed in 0.11.0.
Open WebUI: SSRF into internal services via unvalidated sub-resource requests in the Playwright web loader
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 until 0.11.0, with WEB_LOADER_ENGINE=playwright, the Playwright web loader validates only the top-level page request and lets sub-resource requests pass unvalidated. A page supplied by an authenticated user can use JavaScript to reach blocked internal addresses, and returned DOM can include data read from those addresses in web-search or RAG output. This issue is fixed in 0.11.0.
open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation
open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with allow_origins=* and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests from attacker-controlled websites when an admin user visits them.
Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI
Open WebUI before 0.9.5 contains a stored cross-site scripting vulnerability in the OAuth authentication flow where the picture claim URL MIME type is inferred from file extension rather than Content-Type header, allowing SVG files to bypass the profile image validator and be stored as data URIs. Authenticated users who visit the profile image endpoint receive attacker-controlled SVG content with inline disposition and no default security headers, enabling script execution in the same origin to steal authentication tokens and achieve account takeover.
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.9.6 before 0.10.0, _sanitize_proxy_path in backend/open_webui/routers/terminals.py decoded proxy paths only eight times, allowing a nine-times percent-encoded ../ traversal value to pass normalization checks and be decoded by the upstream terminal server. This issue is fixed in version 0.10.0.
Open WebUI: Arena task endpoints can bypass underlying model access controls
Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.12 before 0.10.0, an authenticated non-admin user with read access to an arena wrapper model can reach a restricted underlying model through task endpoints such as /api/v1/tasks/moa/completions. The normal chat route resolves arena models before the final chat dispatch and therefore re-checks the selected underlying model. The task routes call utils.chat.generate_chat_completion() directly. In that direct path, arena fallback resolution happens after the wrapper access check and then recurses with bypass_filter=True, skipping the selected submodel's