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-2026-2551 Kiwi TCMS vulnerable to stored XSS via JavaScript: URI in extra_link field (TestPlan & TestCase)

Summary In Kiwi TCMS the fields TestCase.extralink and TestPlan.extralink were meant to represent URLs to external resources however in versions prior to 16.1 user input was not being sanitized and values were rendered verbatim which represents an opportunity for cross-site scripting exploitation...

PYSEC-2026-2688 OctoPrint has XSS in its Suppressed Command Notifications

Impact OctoPrint versions up to and including 1.11.7 as well as 2.0.0rc1 and 2.0.0rc2 are affected by a vulnerability that allows injection of arbitrary HTML and JavaScript into Suppressed Command notifications popups generated by the printer. An attacker who successfully convinces a victim to...

PYSEC-2026-2540 jupyterlab-git extension: Stored XSS leading to RCE

Overview Amazon Web Services AWS Security has identified a stored cross-site scripting XSS issue in the jupyterlab-git JupyterLab extension that can lead to remote code execution RCE. The issue exists in the PlainTextDiff.ts component, where the createHeader method passes Git filenames directly t...

PYSEC-2026-2541 jupyterlab-git extension: Stored XSS leading to RCE

Overview Amazon Web Services AWS Security has identified a stored cross-site scripting XSS issue in the jupyterlab-git JupyterLab extension that can lead to remote code execution RCE. The issue exists in the PlainTextDiff.ts component, where the createHeader method passes Git filenames directly t...

PYSEC-2026-2619 marimo contains a reflected cross-site scripting vulnerability in the notebook page

marimo before 0.23.9 contains a reflected cross-site scripting vulnerability in the notebook page that allows unauthenticated attackers to inject arbitrary JavaScript by exploiting improper escaping of single quotes in the file query parameter reflected into an inline JavaScript string literal...

PYSEC-2026-2759 Open WebUI: Stored XSS in Mermaid Markdown Preview

Summary Open WebUI renders Mermaid blocks from Markdown files in the file preview panel and inserts the generated SVG into the DOM using innerHTML. Because Mermaid is configured with securityLevel: 'loose', attacker-controlled Mermaid content can be rendered unsafely in this flow. A working paylo...

PYSEC-2026-2757 Open WebUI: Stored XSS to Account Takeover via Model Profile Images

Stored XSS to Account Takeover via Model Profile Images in Open WebUI Affected: Open WebUI tags. On the output side, users.py added a MIME allowlist check and X-Content-Type-Options: nosniff. The fix was applied to UserUpdateForm, UpdateProfileForm, and later to ChannelWebhookForm. Three models...

PYSEC-2026-2604 Litestar has HTML Injection Through its CSRF Token

Overview Litestar instances which use a template engine in conjunction with CSRF protection are vulnerable to HTML Injection which can be escalated to Cross Site Scripting due to the contents of the CSRF cookie being excluded from automatic escaping by the template engine when configured inline...

PYSEC-2026-2618 malla: Stored XSS via Meshtastic node names in multiple frontend pages

Node names longname, shortname received via MQTT are stored in SQLite without sanitization and rendered into the DOM without escaping. Any participant on a public Meshtastic MQTT broker can set a malicious node name that executes JavaScript in the browser of every Malla dashboard visitor. Affecte...

PYSEC-2026-2694 Open WebUI has XSS via SVG in /api/v1/channels/webhooks/{webhook_id}/profile/image

As part of our research on improving our AI pentest, we have uncovered the following issue in Open WebUI. We've manually verified and tided up the report, but you can also find the original agent finding at the bottom of this report. Summary The channel webhook create/update flow accepts arbitrar...

PYSEC-2026-2748 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-2026-2994 pyLoad is vulnerable to stored XSS in Downloads view via unsanitized link URL in packages.js template literal

Summary The packages.js template at src/pyload/webui/app/themes/modern/templates/js/packages.js:172 interpolates a stored link URL into a template literal inside single-quoted HTML and then writes the result to the DOM via $div.htmlhtml. No escaping runs between the API value and innerHTML. An...

PYSEC-2026-2470 ethyca-fides has a DOM-based XSS vulnerability in fides.js via fides_description override

Summary fides.js is the script that renders Fides's consent banner on customer websites. It lets the embedding page override the banner's description text at runtime via a URL query parameter, a JavaScript global, or a cookie. On sites that have opted into HTML-formatted descriptions, the...

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...

PYSEC-2026-2866 pgAdmin 4: Stored cross-site scripting (XSS) vulnerability in Browser Tree and Explain Visualizer modules

Stored cross-site scripting XSS vulnerability in pgAdmin 4 Browser Tree and Explain Visualizer modules. User-controlled PostgreSQL object names database, schema, table, column, etc. were assigned to DOM elements via innerHTML, allowing crafted object names containing HTML markup to execute...

PYSEC-2026-2744 Open WebUI has stored XSS in Excel file preview

Summary Excel file attachments are previewed in an unsafe way. A crafted XLSX file payload can be used to cause the sheetjs function sheettohtml to embed an XSS payload into the generated HTML. This is subsequently added to the DOM unsanitized via @html causing the payload to trigger. Details The...