CVE-2026-61784

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 v3 6.1 MEDIUM

6.1^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 2.7

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/cstigler/node-xhtml-purifier/commit/21d461ad23e7bc9b3073693d5b51b9b8662044d3
https://github.com/cstigler/node-xhtml-purifier/security/advisories/GHSA-j8r4-32c5-33rc

Configurations

No configuration.

History

24 Sep 2026, 18:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-24 18:17

Updated : 2026-09-30 17:32

NVD link : CVE-2026-61784

Mitre link : CVE-2026-61784

CVE.ORG link : CVE-2026-61784

JSON object : View

Products Affected

No product.

CWE

CWE-79

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CWE-116

Improper Encoding or Escaping of Output

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