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...

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

SummaryOpen 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, complet...

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 ...

SUSE CVE-2026-11322

Hermes WebUI prior to v0.51.221 contains a path traversal vulnerability that allows attackers to escape the workspace boundary by supplying symlinks that resolve to files or directories outside the designated workspace root. Attackers can exploit the workspace file and listing APIs, which resolve...

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-2026-1725 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...

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-2026-1723 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...

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 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-2026-1734 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...

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...

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-2026-1719 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 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...

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 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...

Open WebUI Allows Viewing of Admin Details

An improper access control vulnerability in open-webui/open-webui v0.3.8 allows an attacker to view admin details. The application does not verify whether the attacker is an administrator, allowing the attacker to directly call the /api/v1/auths/admin/details interface to retrieve the first admin...

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...