Open WebUI has an IDOR vulnerability in the update_message_by_id API endpoint

SummaryAn 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. DetailsIn the updatemessagebyid...

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...

Open WebUI: shared-chat branch ignores access_type, allowing unauthorized file deletion

SummaryAny authenticated user can permanently delete files owned by other users via DELETE /api/v1/files/id when the target file is referenced in any shared chat. The hasaccesstofile authorization gate unconditionally grants access through its shared-chat branch. It checks neither the requesting...

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

SummaryA regular user non-admin can view the system prompt of the model which is set by an admin. DetailsWhen 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...

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-2026-2741 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...

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:...

PYSEC-2026-2715 Open WebUI has a Server-Side Request Forgery (SSRF) bypass in `validate_url`

Summary In the open-webui project, a parsing difference between the urlparse and requests libraries led to an SSRF bypass vulnerability. Details In the current project, URL validation is performed using the function validateurl. The current checking logic uses urlparse to parse the hostname part ...

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:...

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...

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 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...

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-2026-2700 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...

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 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 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...