Advisories for Npm/Open-Webui package

2026

Open WebUI: Missing `workspace.tools` Authorization Check on Tool Update Endpoint Allows Privilege Escalation to Code Execution

The tool update endpoint (POST /api/v1/tools/id/{id}/update) is missing the workspace.tools permission check that is present on the tool create endpoint. This allows a user who has been explicitly denied tool management capabilities ( and who the administrator considers untrusted for code execution ) to replace a tool's server-side Python content and trigger execution, bypassing the intended workspace.tools security boundary. Open WebUI's security policy correctly states that workspace.tools is the trust …

Open WebUI has Stored XSS in Banner Component via Improper Sanitization Order

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 …

2025

Open WebUI Vulnerable to Stored DOM XSS via Note 'Download PDF'

A Stored XSS vulnerability has been discovered in Open-WebUI's Notes PDF download functionality. An attacker can import a Markdown file containing malicious SVG tags into Notes, allowing them to execute arbitrary JavaScript code and steal session tokens when a victim downloads the note as PDF. This vulnerability can be exploited by any authenticated user, and unauthenticated external attackers can steal session tokens from users (both admin and regular users) by …

Open WebUI vulnerable to Stored DOM XSS via prompts when 'Insert Prompt as Rich Text' is enabled resulting in ATO/RCE

The functionality that inserts custom prompts into the chat window is vulnerable to DOM XSS when 'Insert Prompt as Rich Text' is enabled, since the prompt body is assigned to the DOM sink .innerHtml without sanitisation. Any user with permissions to create prompts can abuse this to plant a payload that could be triggered by other users if they run the corresponding / command to insert the prompt.

Open WebUI Affected by an External Model Server (Direct Connections) Code Injection via SSE Events

Open WebUI v0.6.33 and below contains a code injection vulnerability in the Direct Connections feature that allows malicious external model servers to execute arbitrary JavaScript in victim browsers via Server-Sent Event (SSE) execute events. This leads to authentication token theft, complete account takeover, and when chained with the Functions API, enables remote code execution on the backend server. The attack requires the victim to enable Direct Connections (disabled by default) …

Open WebUI Uncontrolled Resource Consumption vulnerability

In version v0.3.32 of open-webui/open-webui, the application allows users to submit large payloads in the email and password fields during the sign-in process due to the lack of character length validation on these inputs. This vulnerability can lead to a Denial of Service (DoS) condition when a user submits excessively large strings, exhausting server resources such as CPU, memory, and disk space, and rendering the service unavailable for legitimate users. …

Open WebUI Uncontrolled Resource Consumption vulnerability

In version 0.3.32 of open-webui/open-webui, the absence of authentication mechanisms allows any unauthenticated attacker to access the api/v1/utils/code/format endpoint. If a malicious actor sends a POST request with an excessively high volume of content, the server could become completely unresponsive. This could lead to severe performance issues, causing the server to become unresponsive or experience significant degradation, ultimately resulting in service interruptions for legitimate users.

Open WebUI Unauthenticated Multipart Boundary Denial of Service (DoS) Vulnerability

A Denial of Service (DoS) vulnerability exists in open-webui/open-webui version 0.3.21. This vulnerability affects multiple endpoints, including /ollama/models/upload, /audio/api/v1/transcriptions, and /rag/api/v1/doc. The application processes multipart boundaries without authentication, leading to resource exhaustion. By appending additional characters to the multipart boundary, an attacker can cause the server to parse each byte of the boundary, ultimately leading to service unavailability. This vulnerability can be exploited remotely, resulting in high CPU and memory …