JavaScript is a scripting language used in web pages and applications, where flaws in code or dependencies can enable attacks and data theft.
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Background for this topic.
JavaScript is a programming language used to add behavior to web pages and to build applications that run outside the browser, including server-side services and tooling. In browsers, scripts can read and modify a page’s content and interact with available web APIs, subject to the browser’s security boundaries.
Its main security risks include cross-site scripting (XSS), in which attacker-controlled input is executed as page code, and DOM-based flaws caused by unsafe handling of data in client-side code. Third-party scripts and package dependencies also expand the code supply chain and may expose user data or introduce vulnerable behavior. Practical controls include context-aware output encoding, avoiding unsafe DOM sinks, restrictive Content-Security-Policy rules, and reviewing, pinning, and monitoring dependencies for vulnerabilities.
Cybersecurity researchers are calling attention to an ongoing campaign that distributes fake cryptocurrency trading apps to deploy a compiled V8 JavaScript (JSC) malware called JSCEAL that can capture data from credentials and wallets
React conquered XSS? Think again. That's the reality facing JavaScript developers in 2025, where attackers have quietly evolved their injection techniques to exploit everything from prototype pollution to AI-generated code, bypassing the very frameworks designed to keep applications secure