Openwebui vulnerabilities

Open WebUI from 0.6.31 before 0.11.4 contains a stored cross-site scripting vulnerability in its Markdown renderer, which treats user-authored tool-call details blocks as tool output and mounts their embeds attribute in script-enabled iframes. Authenticated users can post crafted channel messages, chat messages, or citation content that runs JavaScript in viewers' browsers, enabling in-app phishing, or session hijacking where iframeSandboxAllowSameOrigin is enabled.

Open WebUI from 0.9.0 before 0.11.4 contains a denial of service vulnerability that allows authenticated users with automations permission to stall the instance by submitting unsatisfiable recurrence rules. Attackers can repeatedly send rules like February 30th to the automations create or update endpoints, blocking the shared event loop for seconds per request.

Open WebUI 0.11.0 before 0.11.4 compiles user-chosen grep patterns for its knowledge and chat file search tools with a regex engine that expands nested counted repetition unbounded at compile time and caches the result. Authenticated users can have the model call grep_knowledge_files with short nested-repetition patterns, blocking the event loop and exhausting worker memory.

Open WebUI 0.11.0 before 0.11.4 contains a denial of service vulnerability in the automation recurrence-rule validator, whose sub-daily frequency guard parses rule text more strictly than the calendar library that executes it. Users permitted to create automations can submit whitespace-folded rules (or, in 0.11.0, lowercase frequencies or omitted RRULE prefixes) that expand per-second synchronously, blocking the shared event loop for minutes per request and on every scheduler poll.

Open WebUI before 0.11.4 contains a missing authorization vulnerability that allows authenticated users to reach disabled model provider backends by supplying an explicit backend index. Attackers can pass the index as a path segment or query parameter on Ollama and OpenAI-compatible listing routes to trigger requests carrying configured API keys, read version strings, and enumerate connections.

Open WebUI from 0.11.0 before 0.11.4 contains a regular expression denial of service vulnerability that allows authenticated users to stall server workers via file search patterns. Attackers can instruct the model to call grep_knowledge_files or grep_chat_files with a catastrophically backtracking regex, blocking the event loop for two seconds per repeated call.

Open WebUI from 0.6.42 before 0.11.4 contains an uncontrolled resource consumption vulnerability that allows authenticated users to exhaust server memory by supplying compressed remote image URLs in chat messages. Attackers can point the image field at a host returning gzip-encoded responses, which get_image_base64_from_url decompresses unbounded, causing denial of service for all users.

Open WebUI from 0.11.0 before 0.11.4 contains an information disclosure vulnerability that allows authenticated non-admin users with tool export permission to obtain tool source code shared with them read-only. Attackers can request GET /api/v1/tools/export to retrieve the full Python source of read-only shared tools, exposing embedded API keys and credentials.

Open WebUI from 0.6.27 before 0.11.4 contains an information disclosure vulnerability that allows destination servers to obtain user session cookies by receiving the full browser cookie jar on OAuth-mode connections. Operators of OpenAI-compatible connections, OpenAPI tool servers or terminal servers can capture forwarded session cookies from routine requests and replay them to hijack accounts, including administrators.

Open WebUI from 0.8.8 before 0.11.4 contains an improper authorization vulnerability that allows deactivated users to keep executing terminal commands through an already open terminal WebSocket. Because the terminal proxy route in terminals.py checks access only on the first message, deactivated users can keep running commands and reading or writing files on the terminal server.

Open WebUI before 0.11.4 contains a stored cross-site scripting vulnerability in MarkdownInlineTokens.svelte, which renders markdown link URLs into anchor hrefs without validating their scheme. Authenticated users can embed javascript: links in shared chats that, when clicked by a victim, steal the victim's JWT from local storage, including admins' tokens.

Open WebUI from 0.9.6 before 0.11.4 contains an authorization flaw where the knowledge base file listing does not verify that a supplied directory_id belongs to the requested knowledge base. Users with read access to any knowledge base can supply a retained foreign directory UUID to GET /api/v1/knowledge/{id}/files. The returned breadcrumbs expose folder names, owner user ids and knowledge base ids of that directory and all its ancestors.

Open WebUI from 0.6.0 before 0.11.4 contains an improper access control vulnerability in has_access_to_file that lets former knowledge base collaborators keep file access via stale cached knowledge base references. Attackers with read or write grants can download removed files through the file content endpoint or delete them, including from the owner's private knowledge bases.

Open WebUI from 0.11.0 before 0.11.4 contains an improper authorization vulnerability in the chat fork handler, which places forked chats in the source chat's folder without checking folder write access. Shared folder members downgraded to read-only can call POST /api/v1/chats/{id}/fork on chats they created there while they had write access, inserting attacker-controlled chats visible to the folder owner and members.

Open WebUI from 0.11.1 before 0.11.4 contains an authorization bypass in the OAuth token exchange endpoint, which reads role claims only from the provider's userinfo response and keeps the user's existing role when no roles claim is found, ignoring roles sent only in the ID token. Users with a linked account whose identity provider role no longer satisfies the OAuth role policy can send a valid provider access token to POST /api/v1/auths/oauth/{provider}/token/exchange to obtain a session retaining their previous role.

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 affected worker. This issue is fixed in 0.11.0.

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 issue is fixed in 0.11.0.

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 service URLs. This issue is fixed in 0.11.0.

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 HTTP terminal routes correctly reject the same account. This issue is fixed in 0.11.0.

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 fixed in 0.11.0.