EUVD-2026-44628

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...

CVE-2026-56398

Open WebUI before 0.9.5 is vulnerable to stored XSS via the OAuth picture claim SVG data URI. The code infers MIME type from the URL extension (e.g., .svg) and ignores the server-provided Content-Type, then stores data URI labelling it as image/svg+xml. The profile image validator is bypassed in ...

Open WebUI vulnerable to stored XSS via unescaped markdown token in MarkdownTokens.svelte leading to full account takeover and RCE via functions

SummaryA vulnerability in the way certain html tags in chat messages are rendered allows attackers to inject JavaScript code into a chat transcript. The JavaScript code will be executed in the user's browser every time that chat transcript is opened, allowing attackers to retrieve the user's acce...

Open WebUI allows limited stored XSS vila uploaded html file

SummaryLow privileged users can upload HTML files which contain JavaScript code via the /api/v1/files/ backend endpoint. This endpoint returns a file id, which can be used to open the file in the browser and trigger the JavaScript code in the user's browser. Under the default settings, files...

PYSEC-2026-2769 Open WebUI vulnerable to Stored XSS via iFrame in citations model

Summary Manually modifying chat history allows setting the html property within document metadata. This causes the frontend to enter a code path that treats document contents as HTML, and render them in an iFrame when the citation is previewed. This allows stored XSS via a weaponised document...

PYSEC-2026-2736 Open WebUI: Sibling-Prefix Path Traversal via /cache/{path}

Summary A path traversal vulnerability exists in open-webui's cache file serving endpoint that allows any authenticated user to read files from sibling directories outside the intended cache directory, by exploiting an incomplete startswith containment check that lacks a trailing path separator...

PYSEC-2026-2761 Open WebUI: Forged model meta.knowledge allows cross-user file read and deletion

Summary Open WebUI lets a user who can create, update, or import workspace models store arbitrary meta.knowledge entries on their model without checking whether they own or can read the referenced files. Open WebUI then treats meta.knowledge entries of type file as an authorization source in two...

PYSEC-2026-2721 Open WebUI BOLA: `search_knowledge_files` Allows Unauthorized Knowledge Base File Enumeration

Summary Open WebUI has a Broken Object Level Authorization BOLA vulnerability in the builtin searchknowledgefiles tool. When native function calling is enabled and the selected model has no attached knowledge bases, an authenticated user can call searchknowledgefiles with an arbitrary knowledgeid...

PYSEC-2026-2763 Open WebUI: Forged chat-file link allows cross-user file read and deletion

Summary Open WebUI v0.9.5 lets an authenticated user attach arbitrary fileid values to their own chat message without checking whether they own or can read those files. If the attacker then shares that chat and grants themselves read access, hasaccesstofile treats the victim file as accessible...

PYSEC-2026-2695 Open WebUI: Cross-origin postMessage confirmation bypass via action:submit

Summary The chat message listener allows non-same-origin input:prompt and action:submit messages, so an external site can set prompt text and trigger submitPrompt in an authenticated victim session. I validated this with a cross-origin attacker page that auto-posted messages and caused unauthoriz...

PYSEC-2026-2759 Open WebUI: Stored XSS in Mermaid Markdown Preview

Summary Open WebUI renders Mermaid blocks from Markdown files in the file preview panel and inserts the generated SVG into the DOM using innerHTML. Because Mermaid is configured with securityLevel: 'loose', attacker-controlled Mermaid content can be rendered unsafely in this flow. A working paylo...

PYSEC-2026-2751 Open WebUI: Path traversal / SSRF in terminal server proxy via encoded path traversal

Summary The terminal-server reverse proxy in backend/openwebui/routers/terminals.py does not fully confine the user-controlled path segment before forwarding it to an admin-configured terminal server. An authenticated user who has been granted access to a terminal server can craft path values...

PYSEC-2026-2757 Open WebUI: Stored XSS to Account Takeover via Model Profile Images

Stored XSS to Account Takeover via Model Profile Images in Open WebUI Affected: Open WebUI tags. On the output side, users.py added a MIME allowlist check and X-Content-Type-Options: nosniff. The fix was applied to UserUpdateForm, UpdateProfileForm, and later to ChannelWebhookForm. Three models...

PYSEC-2026-2698 Open WebUI: Jupyter code execution works despite `ENABLE_CODE_EXECUTION=false` — feature gate bypassed

Summary The /api/v1/utils/code/execute endpoint executes arbitrary Python code via Jupyter for any verified user, even when the admin has set ENABLECODEEXECUTION=false. The feature gate is not enforced on the API endpoint — the configuration says "disabled" but code still executes. Details The...

PYSEC-2026-2767 Open WebUI has an IDOR vulnerability in the update_message_by_id API endpoint

Summary An IDOR vulnerability exists in the Channels feature of Open WebUI, allowing any channel member to modify messages sent by other members including administrators within the same channel. This vulnerability affects the latest version v0.8.12 of Open WebUI. Details In the updatemessagebyid...

PYSEC-2026-2705 Open WebUI has an IDOR vulnerability in the pin_channel_message API endpoint

Summary Pin/Unpin is a write operation modifies the message's ispinned , pinnedby, pinnedat fields, but in standard channels it only checks read permission, allowing users with read-only access to pin/unpin any message. Details...

PYSEC-2026-2714 Open WebUI: Low-privilege authenticated users can enumerate and stop global background tasks, causing system-wide chat disruption

Summary Any authenticated user with low privileges can enumerate active background tasks across the system and stop tasks belonging to other users via the GET /api/tasks and POST /api/tasks/stop/taskid methods. This allows a casual user to disrupt system-wide chat usage by continuously canceling...

PYSEC-2026-2756 Open WebUI: Mass Assignment via FeedbackForm extra=allow Allows Feedback User ID Spoofing and Evaluation Data Manipulation

Mass Assignment in Feedback Creation Allows User ID Spoofing and Evaluation Data Manipulation Summary The POST /api/v1/evaluations/feedback endpoint in Open WebUI v0.9.2 is vulnerable to mass assignment via FeedbackForm, which uses modelconfig = ConfigDictextra='allow'. Due to an insecure...

PYSEC-2026-2755 Open WebUI has a SSRF Bypass via HTTP Redirect Following in Web-Fetch and Image-Load Endpoints (not addressed by CVE-2025-65958)

Server-Side Request Forgery SSRF Bypass via HTTP Redirect Following in Web-Fetch, Image-Load, and Chat-Completion Endpoints Summary The validateurl function in backend/openwebui/retrieval/web/utils.py only validates the initial URL submitted by the caller. The HTTP clients used downstream sync...

PYSEC-2026-2706 Open WebUI Vulnerable to Unauthenticated RAG Configuration Disclosure

Vulnerability Type: Information Disclosure / Missing Authentication Severity: Medium Component: backend/openwebui/routers/retrieval.py — getstatus GET / Affected Endpoint: GET /api/v1/retrieval/ Affected Version: Open WebUI main branch — confirmed unpatched through v0.9.2 Authentication Required:...