CVE-2026-49458 DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitizenode, INPLACE: true accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, documen...

CVE-2026-49458 DOMPurify: Cross-realm IN_PLACE sanitization leaves executable markup intact via realm-bound `instanceof` checks

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitizenode, INPLACE: true accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, documen...

CVE-2026-49458

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitizenode, INPLACE: true accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, documen...

CVE-2026-47423 DOMPurify XSS via `selectedcontent` re-clone

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. In 3.4.4, DOMPurify allowed selectedcontent by default, allowing browsers to re-clone an XSS payload after sanitization so that unsanitized markup inside is returned. This issue is fixed in version 3.4.5...

CVE-2026-47423

DOMPurify 3.4.4 contains a default allowlist misconfiguration that lets the selectedcontent element bypass sanitization by browser re-cloning after DOMPurify processes the subtree. This creates an XSS risk when attacker-controlled HTML is sanitized and then inserted (e.g., via innerHTML), since t...

CVE-2026-47423 DOMPurify XSS via `selectedcontent` re-clone

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. In 3.4.4, DOMPurify allowed selectedcontent by default, allowing browsers to re-clone an XSS payload after sanitization so that unsanitized markup inside is returned. This issue is fixed in version 3.4.5...

CVE-2026-47423

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. In 3.4.4, DOMPurify allowed selectedcontent by default, allowing browsers to re-clone an XSS payload after sanitization so that unsanitized markup inside is returned. This issue is fixed in version 3.4.5...

EUVD-2026-44443

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. In 3.4.4, DOMPurify allowed selectedcontent by default, allowing browsers to re-clone an XSS payload after sanitization so that unsanitized markup inside is returned. This issue is fixed in version 3.4.5...

CVE-2026-47423 DOMPurify XSS via `selectedcontent` re-clone

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. In 3.4.4, DOMPurify allowed selectedcontent by default, allowing browsers to re-clone an XSS payload after sanitization so that unsanitized markup inside is returned. This issue is fixed in version 3.4.5...

CVE-2026-47423

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. In 3.4.4, DOMPurify allowed selectedcontent by default, allowing browsers to re-clone an XSS payload after sanitization so that unsanitized markup inside is returned. This issue is fixed in version 3.4.5...

CVE-2026-47423: Improper Neutralization of Input During Web Page Generation

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. In 3.4.4, DOMPurify allowed selectedcontent by default, allowing browsers to re-clone an XSS payload after sanitization so that unsanitized markup inside is returned. This issue is fixed in version 3.4.5...

CVE-2026-49458: Improper Neutralization of Input During Web Page Generation

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitizenode, INPLACE: true accepted same-origin foreign-realm DOM nodes while follow-on checks used parent-realm constructors, causing instanceof checks for forms, named node maps, documen...

CVE-2026-49978: Improper Neutralization of Input During Web Page Generation

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.7, DOMPurify INPLACE sanitization could skip shadow contents attached to an element inside...

CVE-2026-49459: Improper Neutralization of Input During Web Page Generation

DOMPurify is a DOM-only cross-site scripting sanitizer for HTML, MathML, and SVG. Prior to 3.4.6, DOMPurify.sanitizeroot, INPLACE: true could preserve event-handler attributes on an attacker-controlled root when a descendant name clobbered properties checked by isClobbered, because forceRemove...

Open WebUI: Stored XSS in Mermaid Markdown Preview

SummaryOpen 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 payload...

PYSEC-2026-2731 Open WebUI has stored XSS via unsanitized Office/Excel/DOCX file preview rendering ({@html} without DOMPurify)

Related advisory This 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...

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...

Open WebUI has Stored XSS in Pending User Overlay via Incorrect DOMPurify Application Order

Vulnerability DetailsCWE-79: Cross-site Scripting XSSThe AccountPending.svelte component renders the admin-configured "Pending User Overlay Content" using marked.parse inside @html with an incorrect DOMPurify application order: Vulnerable Codesrc/lib/components/layout/Overlay/AccountPending.svelt...

PT-2026-59373

Related advisory This 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.sheet to html output rendered via @html excelHtml without DOMPurify — was reintroduced sometim...

DOMPurify: DOMPurify: Cross-Site Scripting (XSS) via inconsistent tag sanitization

A flaw was found in DOMPurify, a DOM-only cross-site scripting sanitizer. A remote attacker could exploit an inconsistency in how forbidden tags and attributes are handled when function-based tag additions are used. This allows malicious HTML, MathML, or SVG elements to bypass sanitization and...