PYSEC-2026-2741 Open WebUI Exposes System Prompt to Regular User [Non-Admin]

Summary A regular user non-admin can view the system prompt of the model which is set by an admin. Details When a regular user non-admin logs into the application, a http://IP:8080/api/models? web request is initiated by the application and in response, it reveals the system prompt of available...

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-2026-2714 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...

Open WebUI vulnerable to blind server side request forgery (SSRF) via the PDF generate function

SummaryBlind server side request forgery SSRF via the PDF generate function. The finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Tested on Open...

PYSEC-2026-2723 Open WebUI vulnerable to blind server side request forgery (SSRF) via the PDF generate function

Summary Blind server side request forgery SSRF via the PDF generate function. The finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Tested on Ope...

Open WebUI missing authorization check at the model update function - models from other users can be updated

SummaryA user can modify another user's model even if its visibility is set to Private.The finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Test...

PYSEC-2026-2738 Open WebUI Vulnerable to Cross-Site Request Forgery (CSRF) via Image URL Manipulation

Summary An application-wide Cross-Site Request Forgery CSRF vulnerability was found Open-WebUl's image uploading functionality. An attacker can set an image URL to a malicious endpoint, allowing them to perform actions on behalf of a victim user. Any authenticated user can exploit this...

Open WebUI Vulnerable to SSRF via OAuth Profile Picture URL in _process_picture_url (oauth.py)

SummaryA Server-Side Request Forgery SSRF vulnerability exists in processpictureurl in backend/openwebui/utils/oauth.py line 1338. The function fetches arbitrary URLs from OAuth picture claims without applying validateurl, allowing an attacker to force the server to make HTTP requests to internal...

Open WebUI has Broken Access Control for Completions API

SummaryAny user X can continue the conversation of any other user Y, as long as the Chat ID of Y is known. User X does not even need to be an admin to do so. DetailsA user just needs to use the API endpoint: /api/chat/completions with their own API key generated in OWUI and the Chat ID of another...

Open WebUI has stored XSS via unsanitized Office/Excel/DOCX file preview rendering ({@html} without DOMPurify)

Related advisoryThis advisory tracks a regression of the original Excel-preview XSS that was publicly disclosed and patched under GHSA-jwf8-pv5p-vhmc patched in v0.8.0. The same root cause — XLSX.utils.sheettohtml output rendered via @html excelHtml without DOMPurify — was reintroduced sometime...

Open WebUI Vulnerable to Cross-Site Request Forgery (CSRF) via Image URL Manipulation

SummaryAn application-wide Cross-Site Request Forgery CSRFvulnerability was found Open-WebUl's image uploading functionality. An attacker can set an image URL to a malicious endpoint, allowing them to perform actions on behalf of a victim user. Any authenticated user can exploit this vulnerabilit...

Open WebUI has stored XSS via attacker-controlled file extension in /api/v1/audio/transcriptions

Summary The audio transcription upload endpoint takes the file extension from the user-supplied filename and saves the file under CACHEDIR/audio/transcriptions/.. The /cache/path route serves these files via FileResponse, which sets Content-Type from the on-disk extension and emits no...

PYSEC-2026-2745 Open WebUI: Read-Only Users Can Toggle Note Pin Status via Incorrect Permission Check (Write via Read-Only Access)

Summary The POST /api/v1/notes/id/pin endpoint performs a write operation toggling the ispinned field but only checks for read permission. Users with read-only access to a shared note can pin/unpin it, which is a state-modifying action that should require write permission. All other write endpoin...

Open WebUI: Read-Only Users Can Toggle Note Pin Status via Incorrect Permission Check (Write via Read-Only Access)

SummaryThe POST /api/v1/notes/id/pin endpoint performs a write operation toggling the ispinned field but only checks for read permission. Users with read-only access to a shared note can pin/unpin it, which is a state-modifying action that should require write permission. All other write endpoint...

Open WebUI's chat completion API allows tool restrictions to be bypassed

SummaryOpen WebUI v0.6.43 contains a vulnerability in its chat completion API, which allows attackers to bypass tool restrictions, potentially enabling unauthorized actions or access. DetailsIn the chatcompletion API, the parameters toolids and toolservers are supplied by the user. These paramete...

PYSEC-2026-2700 Open WebUI's chat completion API allows tool restrictions to be bypassed

Summary Open WebUI v0.6.43 contains a vulnerability in its chat completion API, which allows attackers to bypass tool restrictions, potentially enabling unauthorized actions or access. Details In the chatcompletion API, the parameters toolids and toolservers are supplied by the user. These...

Open WebUI has stored XSS via the HTML renedering view

SummaryThrough the HTML rendering view, scripts can be injected and executed. The finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Tested on Ope...

PYSEC-2026-2704 Open WebUI has stored XSS via the HTML renedering view

Summary Through the HTML rendering view, scripts can be injected and executed. The finding resulted from a penetration test for a customer. It is suspected that the root cause of the issue lies within the core of Open WebUI, which is why it is being reported as a security issue here. Tested on Op...

PYSEC-2026-2708 Open WebUI has Stored Cross-Site Scripting In Profile Picture

Summary The profileimageurl field on the user profile update form accepted arbitrary data: URI values without MIME-type validation. Two distinct attack paths were independently demonstrated by separate reporters: 1. data:text/html;base64,... in a new browser tab raresvis, 2025-04-17 — when a vict...

Open WebUI Arbitrary File Write, Delete via Path Traversal

CONFIDENTIAL Vulnerability Disclosure Analysis Documentation-----------------------------------------------Vulnerability Details---------------------1. Discoverer: Taylor Pennington of KoreLogic, Inc.2. Date Submitted: June 11, 20243. Title: Open WebUI Arbitrary File Write, Delete via Path...