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-2026-2759 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-2026-2604 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-2026-2708 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-2026-2470 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-2026-2866 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...

PYSEC-2026-2724 Open WebUI has Stored XSS in Pending User Overlay via Incorrect DOMPurify Application Order

Vulnerability Details CWE-79: Cross-site Scripting XSS The AccountPending.svelte component renders the admin-configured "Pending User Overlay Content" using marked.parse inside @html with an incorrect DOMPurify application order: Vulnerable Code...

PYSEC-2026-2891 Postorius is vulnerable to XSS

Postorius through 1.3.13 does not escape HTML in the message subject when rendering it in the Held messages pop-up, as exploited in the wild in May 2026...

PYSEC-2026-2538 Jupyter Notebook Vulnerable to Authentication Token Theft via CommandLinker XSS

Impact A stored Cross-Site Scripting XSS vulnerability in Jupyter Notebook allows attackers to steal authentication tokens from users who open malicious notebook files and interact with elements that the attacker can make look indistinguishable from legitimate controls single click interaction. T...

PYSEC-2026-2682 Jupyter Notebook Vulnerable to Authentication Token Theft via CommandLinker XSS

Impact A stored Cross-Site Scripting XSS vulnerability in Jupyter Notebook allows attackers to steal authentication tokens from users who open malicious notebook files and interact with elements that the attacker can make look indistinguishable from legitimate controls single click interaction. T...

beets has a Cross-site Scripting vulnerability

During code logic analyis, an area that may lead to unintended behavior under specific conditions was discovered. Overview- Verified Version: 80cd21554124da07d17a4f962c7d770a4f70d0f2- Vulnerability Type: Stored XSS- Affected Location: beetsplug/web/templates/index.html:42- Trigger Scenario:...

PYSEC-2026-2397 beets has a Cross-site Scripting vulnerability

During code logic analyis, an area that may lead to unintended behavior under specific conditions was discovered. Overview - Verified Version: 80cd21554124da07d17a4f962c7d770a4f70d0f2 - Vulnerability Type: Stored XSS - Affected Location: beetsplug/web/templates/index.html:42 - Trigger Scenario:...

PYSEC-2026-3419 wger has Stored XSS via Unescaped License Attribution Fields

Stored XSS via Unescaped License Attribution Fields Summary The AbstractLicenseModel.attributionlink property in wger/utils/models.py constructs HTML strings by directly interpolating user-controlled fields licenseauthor, licensetitle, licenseobjecturl, licenseauthorurl, licensederivativesourceur...

PYSEC-2026-2910 PraisonAI Vulnerable to Stored XSS via Unsanitized Agent Output in HTML Rendering (nh3 Not a Required Dependency)

Summary The Flask API endpoint in src/praisonai/api.py renders agent output as HTML without effective sanitization. The sanitizehtml function relies on the nh3 library, which is not listed as a required or optional dependency in pyproject.toml. When nh3 is absent the default installation, the...