Upgrading from jQuery v2.1.3 is not as painful as you might think, provided you follow a structured approach.
: You can use tools like the Snyk Vulnerability Database to scan your specific codebase for these and other dependencies. 1.3 to a more secure version of jQuery? jquery v2.1.3 vulnerabilities
// In jQuery v2.1.3, this pollutes Object.prototype var malicious = JSON.parse('{"__proto__": {"isAdmin": true}}'); $.extend(true, {}, malicious); Upgrading from jQuery v2
Even after upgrading, never trust user input. Do not rely on jQuery's internal handling. Use a dedicated sanitizer library: // In jQuery v2
The fix is straightforward but requires diligence. Upgrade to the 3.x branch, patch your code for breaking changes, and implement a Content Security Policy (CSP) as a second line of defense. If you cannot upgrade due to legacy constraints, isolate the jQuery code behind a web application firewall (WAF) that blocks common XSS patterns.
Every day jQuery v2.1.3 remains in production, your users are one crafted comment or phishing link away from complete compromise. Update today.
Sources: jQuery Official Security Blog, Snyk Vulnerability DB, CVE Mitre, OWASP Cheat Sheet Series.