open-webui is Vulnerable to Incorrect Access Control

open-webui v0.6.33 is vulnerable to Incorrect Access Control. The API /api/tasks/stop/ directly accesses and cancels tasks without verifying user ownership, enabling attackers a normal user to stop arbitrary LLM response tasks...

PYSEC-2026-1741 Open WebUI vulnerable to Stored DOM XSS via prompts when 'Insert Prompt as Rich Text' is enabled resulting in ATO/RCE

Summary 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 ...

PYSEC-2026-1729 Open WebUI Affected by an External Model Server (Direct Connections) Code Injection via SSE Events

Summary 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, comple...

PYSEC-2026-1725 Open WebUI lacks authentication for the `api/v1/utils/pdf` endpoint

In version v0.3.10 of open-webui/open-webui, the api/v1/utils/pdf endpoint lacks authentication mechanisms, allowing unauthenticated attackers to access the PDF generation service. This vulnerability can be exploited by sending a POST request with an excessively large payload, potentially leading...

Open WebUI lacks authentication for the `api/v1/utils/pdf` endpoint

In version v0.3.10 of open-webui/open-webui, the api/v1/utils/pdf endpoint lacks authentication mechanisms, allowing unauthenticated attackers to access the PDF generation service. This vulnerability can be exploited by sending a POST request with an excessively large payload, potentially leading...

PYSEC-2026-1734 Open WebUI stored cross-site scripting (XSS) vulnerability

A stored cross-site scripting XSS vulnerability exists in open-webui/open-webui version 0.3.8. The vulnerability is present in the /api/v1/models/add endpoint, where the model description field is improperly sanitized before being rendered in chat. This allows an attacker to inject malicious...

Open WebUI denial of service through endpoint for converting markdown

In version 0.3.8 of open-webui, an endpoint for converting markdown to HTML is exposed without authentication. A maliciously crafted markdown payload can cause the server to spend excessive time converting it, leading to a denial of service. The server becomes unresponsive to other requests until...

PYSEC-2026-1723 Open WebUI denial of service through endpoint for converting markdown

In version 0.3.8 of open-webui, an endpoint for converting markdown to HTML is exposed without authentication. A maliciously crafted markdown payload can cause the server to spend excessive time converting it, leading to a denial of service. The server becomes unresponsive to other requests until...

PYSEC-2026-1727 Open WebUI Has Improper Access Control Leading to Arbitrary Prompt Read

In version v0.3.8 of open-webui/open-webui, improper access control vulnerabilities allow an attacker to view any prompts. The application does not verify whether the attacker is an administrator, allowing the attacker to directly call the /api/v1/prompts/ interface to retrieve all prompt...

PYSEC-2026-1719 Open WebUI Allows Arbitrary File Write via the `download_model` Endpoint

In version 0.3.8 of open-webui/open-webui, an arbitrary file write vulnerability exists in the downloadmodel endpoint. When deployed on Windows, the application improperly handles file paths, allowing an attacker to manipulate the file path to write files to arbitrary locations on the server's...

Open WebUI Vulnerable to Cross-Site Request Forgery (CSRF)

In version v0.3.8 of open-webui/open-webui, sensitive actions such as deleting and resetting are performed using the GET method. This vulnerability allows an attacker to perform Cross-Site Request Forgery CSRF attacks, where an unaware user can unintentionally perform sensitive actions by simply...

Open WebUI has SSRF in /openai/models

The /openai/models endpoint in open-webui/open-webui version 0.3.8 is vulnerable to Server-Side Request Forgery SSRF. An attacker can change the OpenAI URL to any URL without checks, causing the endpoint to send a request to the specified URL and return the output. This vulnerability allows the...

PYSEC-2026-1724 Open WebUI Cross-Site Request Forgery (CSRF) Vulnerability

A vulnerability in open-webui/open-webui versions = 0.3.8 allows remote code execution by non-admin users via Cross-Site Request Forgery CSRF. The application uses cookies with the SameSite attribute set to lax for authentication and lacks CSRF tokens. This allows an attacker to craft a malicious...

PYSEC-2026-1720 Open WebUI Vulnerable to a Session Fixation Attack

A vulnerability in open-webui/open-webui version 0.3.8 allows an attacker with a user-level account to perform a session fixation attack. The session cookie for all users is set with the default SameSite=Lax and does not have the Secure flag enabled, allowing the session cookie to be sent over HT...

PYSEC-2026-1739 Open WebUI Vulnerable to Cross-Site Request Forgery (CSRF)

In version v0.3.8 of open-webui/open-webui, sensitive actions such as deleting and resetting are performed using the GET method. This vulnerability allows an attacker to perform Cross-Site Request Forgery CSRF attacks, where an unaware user can unintentionally perform sensitive actions by simply...

Open WebUI Allows Arbitrary File Write via the `/models/upload` Endpoint

In open-webui version 0.3.8, the endpoint /models/upload is vulnerable to arbitrary file write due to improper handling of user-supplied filenames. The vulnerability arises from the usage of filepath = f"UPLOADDIR/file.filename" without proper input validation or sanitization. An attacker can...

Open WebUI Allows Admin Deletion via API Endpoint

In open-webui/open-webui version v0.3.8, there is an improper privilege management vulnerability. The application allows an attacker, acting as an admin, to delete other administrators via the API endpoint http://0.0.0.0:8080/api/v1/users/uuidadministrator. This action is restricted by the user...

PYSEC-2026-1736 Open WebUI Vulnerable to Cross-Site Scripting (XSS) via Chat File Upload

A Stored Cross-Site Scripting XSS vulnerability exists in the chat file upload functionality of open-webui/open-webui version 0.3.8. An attacker can inject malicious content into a file, which, when accessed by a victim through a URL or shared chat, executes JavaScript in the victim's browser. Th...

PYSEC-2026-1737 Open WebUI Allows Arbitrary File Reading and Deletion

An improper access control vulnerability in open-webui/open-webui v0.3.8 allows attackers to view and delete any files. The application does not verify whether the attacker is an administrator, allowing the attacker to directly call the GET /api/v1/files/ interface to retrieve information on all...

PYSEC-2026-1742 Open WebUI Uncontrolled Resource Consumption vulnerability

A vulnerability in open-webui/open-webui v0.3.8 allows an unauthenticated attacker to sign up with excessively large text in the 'name' field, causing the Admin panel to become unresponsive. This prevents administrators from performing essential user management actions such as deleting, editing, ...