Improper Encoding or Escaping of Output Affecting xhtml-purifier package, versions <0.4.3
Threat Intelligence
Snyk has a proof-of-concept or detailed explanation of how to exploit this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JS-XHTMLPURIFIER-21694027
- published24 Oct 2026
- disclosed24 Sept 2026
- creditUnknown
Introduced: 24 Sep 2026
CVE-2026-61784 (opens in a new tab)How to fix?
Upgrade xhtml-purifier to version 0.4.3 or higher.
Overview
xhtml-purifier is a Simple HTML purifier/cleaner for untrusted HTML.
Affected versions of this package are vulnerable to Improper Encoding or Escaping of Output via the attributeString() function in XHTMLPurifier.js, which writes attribute values into double-quoted HTML attributes without entity-encoding them. An attacker who controls an attribute value containing a double-quote character can break out of the quoted attribute context and inject arbitrary additional attributes, including event handlers such as onmouseover, which execute when the purified output is rendered in a browser.