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CVE-2026-61784

CVE-2026-61784 · xhtml-purifier has HTML attribute-injection (sanitizer bypass) that leads to XSS

This page contains facts from public vulnerability sources. Check the original advisory before updating.

xhtml-purifier is a Node.js library to take in raw/unknown/untrusted HTML and output cleaned, purified, trusted HTML. Versions prior to 0.4.3 do not HTML-entity-encode attribute values when serializing its sanitized output. In attributeString() (XHTMLPurifier.js, around line 148) the attribute value is concatenated directly into a double-quoted attribute without encoding. As a result, an attacker-controlled value in any allowed attribute (class, style, title, alt, src, href) can include a double-quote character to break out of the attribute and inject an additional attribute, such as a JavaScript event handler (for example onmouseover or onerror). The injected handler survives sanitization and executes when the output is rendered, which is a sanitizer bypass leading to cross-site scripting. The fix in version 0.4.3 HTML-entity-encodes attribute values before serialization.

CVSS 6.1 · Medium · EPSS 0.2% · Fix available

Published
Updated

Stack: node

Affected products and versions

Original sources

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