Linkify Allows Prototype Pollution & HTML Attribute Injection (XSS)
Date: 2025-07
Affected: npm/linkifyjs
Attack vector: xss
Category: vulnerability-disclosure
Severity: High
CVE: CVE-2025-8101
CWE: CWE-1321

Prototype Pollution in internal `assign()` helper in Linkify allows remote attackers to execute arbitrary JavaScript (Stored or Reflected XSS) via injection of event handlers through unfiltered proto property. This issue affects Linkify version 4.3.1 and is fixed in 4.3.2.


Mitigations:

Architectural layers (MAESTRO):