GHSA-FFPJ-XV5C-P3GW Open WebUI: ReDoS in skill-mention regexes causes whole-instance DoS on default config

Summary Two regexes in backend/openwebui/utils/middleware.py that parse skill-mention tags backtrack in On² on input that contains . Both run synchronously, on the asyncio event loop, on every chat completion with no feature gate. Because the default deployment is a single uvicorn worker, one suc...

EUVD-2026-42620

Open WebUI: Scheduled automations continue after pending-user deactivation and stored model ACL revocation...

EUVD-2026-42616

Open WebUI: Stored web worker XSS via Pyodide...

GHSA-PG7V-JWJ7-P798 vulnerabilities

Vulnerabilities for packages: superset, mlflow, open-webui...

CVE-2026-59203 vulnerabilities

Vulnerabilities for packages: superset, mlflow, open-webui...

PYSEC-2026-3543 Open WebUI's API key endpoint restrictions bypassed via `x-api-key` header — full message processing on restricted endpoints

Summary Open WebUI allows admins to restrict which API endpoints an API key can access. When an API key is restricted from /api/v1/messages, requests using the Authorization: Bearer sk-... header are correctly blocked with 403. However, the same key sent via the x-api-key header bypasses the...

CVE-2026-56400

open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with alloworigins= and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests...

CVE-2026-56398

Open WebUI before 0.9.5 contains a stored cross-site scripting vulnerability in the OAuth authentication flow where the picture claim URL MIME type is inferred from file extension rather than Content-Type header, allowing SVG files to bypass the profile image validator and be stored as data URIs...

CVE-2026-56400 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation

open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with alloworigins= and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests...

CVE-2026-56400 open-webui - Remote Code Execution via CORS Misconfiguration and Session Validation

open-webui before 0.3.14 contains a cross-origin resource sharing misconfiguration allowing arbitrary origins with alloworigins= and authenticated requests to the /api/v1/functions endpoint. Attackers can execute arbitrary code on the openwebui instance by crafting malicious cross-site requests...

CVE-2026-56400

open-webui before 0.3.14 is described as vulnerable to a cross-origin resource sharing misconfiguration that allows arbitrary origins (allow_origins=*) and authenticated requests to the /api/v1/functions endpoint. The result is remote code execution by crafting malicious cross-site requests from ...

CVE-2026-56398 Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI

Open WebUI before 0.9.5 contains a stored cross-site scripting vulnerability in the OAuth authentication flow where the picture claim URL MIME type is inferred from file extension rather than Content-Type header, allowing SVG files to bypass the profile image validator and be stored as data URIs...

CVE-2026-56398 Open WebUI - Stored Cross-Site Scripting via OAuth Picture Claim SVG Data URI

Open WebUI before 0.9.5 contains a stored cross-site scripting vulnerability in the OAuth authentication flow where the picture claim URL MIME type is inferred from file extension rather than Content-Type header, allowing SVG files to bypass the profile image validator and be stored as data URIs...

CVE-2026-56398

Open WebUI before 0.9.5 is vulnerable to stored XSS via the OAuth picture claim SVG data URI. The code infers MIME type from the URL extension (e.g., .svg) and ignores the server-provided Content-Type, then stores data URI labelling it as image/svg+xml. The profile image validator is bypassed in ...

EUVD-2026-44628

Open WebUI before 0.9.5 contains a stored cross-site scripting vulnerability in the OAuth authentication flow where the picture claim URL MIME type is inferred from file extension rather than Content-Type header, allowing SVG files to bypass the profile image validator and be stored as data URIs...

Open WebUI vulnerable to stored XSS via unescaped markdown token in MarkdownTokens.svelte leading to full account takeover and RCE via functions

SummaryA vulnerability in the way certain html tags in chat messages are rendered allows attackers to inject JavaScript code into a chat transcript. The JavaScript code will be executed in the user's browser every time that chat transcript is opened, allowing attackers to retrieve the user's acce...

Open WebUI allows limited stored XSS vila uploaded html file

SummaryLow privileged users can upload HTML files which contain JavaScript code via the /api/v1/files/ backend endpoint. This endpoint returns a file id, which can be used to open the file in the browser and trigger the JavaScript code in the user's browser. Under the default settings, files...

PYSEC-2026-2769 Open WebUI vulnerable to Stored XSS via iFrame in citations model

Summary Manually modifying chat history allows setting the html property within document metadata. This causes the frontend to enter a code path that treats document contents as HTML, and render them in an iFrame when the citation is previewed. This allows stored XSS via a weaponised document...

PYSEC-2026-2736 Open WebUI: Sibling-Prefix Path Traversal via /cache/{path}

Summary A path traversal vulnerability exists in open-webui's cache file serving endpoint that allows any authenticated user to read files from sibling directories outside the intended cache directory, by exploiting an incomplete startswith containment check that lacks a trailing path separator...

PYSEC-2026-2761 Open WebUI: Forged model meta.knowledge allows cross-user file read and deletion

Summary Open WebUI lets a user who can create, update, or import workspace models store arbitrary meta.knowledge entries on their model without checking whether they own or can read the referenced files. Open WebUI then treats meta.knowledge entries of type file as an authorization source in two...