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...

PT-2026-50483

Name of the Vulnerable Software and Affected Versions Open WebUI versions prior to 0.9.6 Description The application 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:...

GHSA-VXR8-FQ34-VVX9 DOMPurify: Trusted Types policy survives `clearConfig()` and can poison later `RETURN_TRUSTED_TYPE` output

Impact A DOMPurify instance that is reused across trust boundaries can stay bound to a previously supplied TRUSTEDTYPESPOLICY even after clearConfig is called. A later caller that requests RETURNTRUSTEDTYPE receives a TrustedHTML object created by the old policy, not by a clean default...

Protection Mechanism Failure

Overview org.webjars.npm:dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG. Affected versions of this package are vulnerable to Protection Mechanism Failure through the clearConfig function. An attacker can execute arbitrary scripts in a Trusted Types sink by influencing a previously...

DOMPurify: Trusted Types policy survives `clearConfig()` and can poison later `RETURN_TRUSTED_TYPE` output

Impact A DOMPurify instance that is reused across trust boundaries can stay bound to a previously supplied TRUSTEDTYPESPOLICY even after clearConfig is called. A later caller that requests RETURNTRUSTEDTYPE receives a TrustedHTML object created by the old policy, not by a clean default...

DOMPurify: SAFE_FOR_TEMPLATES bypass - template expressions survive sanitization inside <template> content when using DOM output modes

Summary When DOMPurify is configured with both SAFEFORTEMPLATES: true and RETURNDOM: true or INPLACE: true, an attacker can inject template expressions, such as $evil, evil, or , that survive the sanitization pass inside element content. This bypasses the explicit purpose of SAFEFORTEMPLATES, whi...

Cross-site Scripting (XSS)

Overview org.webjars.npm:dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG. Affected versions of this package are vulnerable to Cross-site Scripting XSS in the SAFEFORTEMPLATES function. An attacker can inject template expressions that survive sanitization inside element content by...

Cross-site Scripting (XSS)

Overview org.webjars.npm:dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG. Affected versions of this package are vulnerable to Cross-site Scripting XSS in the INPLACE function when handling a element containing an element with an attached shadow DOM. An attacker can execute arbitrar...

DOMPurify IN_PLACE Sanitization Bypass via Attached Shadow Root Inside <template>.content

If the HTML you give it contains a element, and inside that template there's an element with a shadow DOM attached to it, DOMPurify quietly skips over the shadow contents. Whatever the attacker put in there - an image with an onerror handler, a link with a javascript: URL, even a full script -...

GHSA-RP9W-3FW7-7CWQ DOMPurify IN_PLACE Sanitization Bypass via Attached Shadow Root Inside <template>.content

If the HTML you give it contains a element, and inside that template there's an element with a shadow DOM attached to it, DOMPurify quietly skips over the shadow contents. Whatever the attacker put in there - an image with an onerror handler, a link with a javascript: URL, even a full script -...

GHSA-X4VX-RJVF-J5P4 DOMPurify: `IN_PLACE` mode trusts attacker-controlled `nodeName` on live non-form nodes, allowing script retention and XSS via attacker-supplied DOM objects

Summary When DOMPurify.sanitizeroot, INPLACE: true is called on an attacker-supplied live DOM node, DOMPurify still trusts currentNode.nodeName for non-form nodes in the main sanitizeElements pipeline. A real child node whose observable nodeName is attacker-controlled can therefore be misclassifi...

DOMPurify: `IN_PLACE` mode trusts attacker-controlled `nodeName` on live non-form nodes, allowing script retention and XSS via attacker-supplied DOM objects

Summary When DOMPurify.sanitizeroot, INPLACE: true is called on an attacker-supplied live DOM node, DOMPurify still trusts currentNode.nodeName for non-form nodes in the main sanitizeElements pipeline. A real child node whose observable nodeName is attacker-controlled can therefore be misclassifi...

Cross-site Scripting (XSS)

Overview org.webjars.npm:dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG. Affected versions of this package are vulnerable to Cross-site Scripting XSS in the INPLACE process when attacker-controlled live DOM nodes are sanitized. An attacker can execute arbitrary scripts in the...

Trust Boundary Violation

Overview org.webjars.npm:dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG. Affected versions of this package are vulnerable to Trust Boundary Violation through the mutation of data.allowedTags or data.allowedAttributes in hooks, which directly alters the global default sets used for...

DOMPurify: Hook mutation of `data.allowedTags` / `data.allowedAttributes` permanently pollutes `DEFAULT_ALLOWED_TAGS` / `DEFAULT_ALLOWED_ATTR`

Hook mutation of data.allowedTags / data.allowedAttributes permanently pollutes DEFAULTALLOWEDTAGS / DEFAULTALLOWEDATTR CWE: CWE-501 Trust Boundary Violation — hook-scoped mutation leaks to global default sets via CWE-693 Protection Mechanism Failure — the default allow-list is silently widened f...

GHSA-76MC-F452-CXCM DOMPurify: Hook mutation of `data.allowedTags` / `data.allowedAttributes` permanently pollutes `DEFAULT_ALLOWED_TAGS` / `DEFAULT_ALLOWED_ATTR`

Hook mutation of data.allowedTags / data.allowedAttributes permanently pollutes DEFAULTALLOWEDTAGS / DEFAULTALLOWEDATTR CWE: CWE-501 Trust Boundary Violation — hook-scoped mutation leaks to global default sets via CWE-693 Protection Mechanism Failure — the default allow-list is silently widened f...

Trust Boundary Violation

Overview org.webjars.npm:dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG. Affected versions of this package are vulnerable to Trust Boundary Violation in the sanitize function when handling DOM nodes from a different same-origin realm due to improper realm-bound instanceof checks. ...

DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks

Cross-realm INPLACE sanitization leaves executable markup intact via realm-bound instanceof checks CWE: CWE-79 XSS — Improper Neutralization of Input During Web Page Generation via CWE-693 Protection Mechanism Failure — realm-bound instanceof checks fail-open on foreign-realm DOM nodes and CWE-50...

Prototype Pollution

Overview org.webjars.npm:dompurify is a DOM-only XSS sanitizer for HTML, MathML and SVG. Affected versions of this package are vulnerable to Prototype Pollution in the INPLACE function when sanitizing a root element that is a with event handler attributes and a descendant element whose name...

GHSA-R47G-FVHR-H676 DOMPurify: IN_PLACE mode preserves attributes of a clobbered root element, allowing XSS via attacker-controlled root DOM

INPLACE mode preserves attributes of a clobbered root element, allowing XSS via attacker-controlled root DOM CWE: CWE-79 XSS — Improper Neutralization of Input During Web Page Generation via CWE-693 Protection Mechanism Failure — silent no-op when forceRemove is called on a parent-less node Summa...