Security-focused ESLint plugin for browser applications. Detects XSS vulnerabilities, postMessage abuse, localStorage/sessionStorage/IndexedDB token exposure, cookie security issues, WebSocket security, Blob URL leaks, Service Worker risks, and CSP miscon
npm install eslint-plugin-browser-security
Browser-specific security rules to prevent XSS and other client-side attacks.
This plugin provides Browser-specific security rules to prevent XSS and other client-side attacks.
By using this plugin, you can proactively identify and mitigate security risks across your entire codebase.
Interlace fosters strength through integration. Instead of stacking isolated rules, we interlace security directly into your workflow to create a resilient fabric of code. We believe tools should guide rather than gatekeep, providing educational feedback that strengthens the developer with every interaction.
- To check out the guide, visit eslint.interlace.tools. ๐
- ่ฆๆฅ็ไธญๆ ๆๅ, ่ฏท่ฎฟ้ฎ eslint.interlace.tools. ๐
- ๊ฐ์ด๋ ๋ฌธ์๋ eslint.interlace.tools์์ ํ์ธํ์ค ์ ์์ต๋๋ค. ๐
- ใฌใคใใฏ eslint.interlace.toolsใงใ็ขบ่ชใใ ใใใ ๐
- Para ver la guรญa, visita eslint.interlace.tools. ๐
- ููุงุทูุงุน ุนูู ุงูุฏูููุ ูู
ุจุฒูุงุฑุฉ eslint.interlace.tools. ๐
``bash`
npm install eslint-plugin-browser-security --save-dev
- XSS Prevention: Detects dangerous DOM manipulation patterns
- Storage Security: Prevents sensitive data exposure in localStorage/sessionStorage/IndexedDB
- Cross-Origin Protection: Validates postMessage origin checks
- Cookie Security: Identifies insecure cookie handling in JavaScript
- LLM-Optimized: All rules include AI-friendly remediation guidance
`javascript
// XSS via innerHTML
element.innerHTML = userInput;
// Code injection via eval
eval(dynamicCode);
// JWT in localStorage (XSS can steal it)
localStorage.setItem('token', jwt);
// postMessage without origin check
window.addEventListener('message', (event) => {
processData(event.data); // Anyone can send messages!
});
`
`javascript
// Safe text assignment
element.textContent = userInput;
// Or sanitize before HTML insertion
element.innerHTML = DOMPurify.sanitize(userInput);
// Use HttpOnly cookies for auth tokens (set by server)
// Server: Set-Cookie: token=xxx; HttpOnly; Secure; SameSite=Strict
// Origin validation
window.addEventListener('message', (event) => {
if (event.origin !== 'https://trusted-domain.com') return;
processData(event.data);
});
`
| Recommended security configuration |
| strict | Strict security configuration - all rules as errors |๐ค LLM-Optimized Messages
All rules include structured remediation guidance designed for AI assistants:`
[browser-security/no-innerhtml] XSS vulnerability: Direct HTML assignment detected.๐ CONTEXT:
โข Pattern: element.innerHTML = unsanitizedInput
โข Risk: Any script in unsanitizedInput will execute
๐ ๏ธ REMEDIATION:
Option A (Preferred): Use textContent for plain text
element.textContent = userInput;
Option B: Sanitize before insertion
element.innerHTML = DOMPurify.sanitize(userInput);
๐ References:
โข CWE-79: https://cwe.mitre.org/data/definitions/79.html
โข OWASP XSS Prevention: https://owasp.org/...
`By providing this structured context (CWE, OWASP, Fix), we enable AI tools to reason about the security flaw rather than hallucinating. This allows Copilot/Cursor to suggest the _exact_ correct fix immediately.
Rules
Legend
| Icon | Description |
| :---: | :--- |
| ๐ผ | Recommended: Included in the recommended preset. |
| โ ๏ธ | Warns: Set towarn in recommended preset. |
| ๐ง | Auto-fixable: Automatically fixable by the
--fix CLI option. |
| ๐ก | Suggestions: Providing code suggestions in IDE. |
| ๐ซ | Deprecated: This rule is deprecated. || Rule | CWE | OWASP | CVSS | Description | ๐ผ | โ ๏ธ | ๐ง | ๐ก | ๐ซ |
| :--- | :---: | :---: | :---: | :--- | :---: | :---: | :---: | :---: | :---: |
| detect-mixed-content | | | | ESLint rule documentation for detect-mixed-content | | | | | |
| no-allow-arbitrary-loads | | | | ESLint rule documentation for no-allow-arbitrary-loads | | | | | |
| no-clickjacking | | | | ESLint rule documentation for no-clickjacking | | | | | |
| no-client-side-auth-logic | | | | ESLint rule documentation for no-client-side-auth-logic | | | | | |
| no-cookie-auth-tokens | CWE-1004 | A02:2025 | 5.3 | ESLint rule documentation for no-cookie-auth-tokens | ๐ผ | | | ๐ก | |
| no-credentials-in-query-params | | | | ESLint rule documentation for no-credentials-in-query-params | | | | | |
| no-disabled-certificate-validation | | | | ESLint rule documentation for no-disabled-certificate-validation | | | | | |
| no-dynamic-service-worker-url | CWE-829 | A08:2025 | 7.5 | ESLint rule documentation for no-dynamic-service-worker-url | ๐ผ | | | ๐ก | |
| no-eval | CWE-95 | A03:2025 | 9.8 | ESLint rule documentation for no-eval | ๐ผ | | | ๐ก | ๐ซ |
| no-filereader-innerhtml | CWE-79 | A03:2025 | 6.1 | ESLint rule documentation for no-filereader-innerhtml | ๐ผ | | | ๐ก | |
| no-http-urls | | | | ESLint rule documentation for no-http-urls | | | | | |
| no-innerhtml | CWE-79 | A03:2025 | 6.1 | ESLint rule documentation for no-innerhtml | ๐ผ | | | ๐ก | |
| no-insecure-redirects | | | | ESLint rule documentation for no-insecure-redirects | | | | | |
| no-insecure-websocket | | | | ESLint rule documentation for no-insecure-websocket | | | | | |
| no-jwt-in-storage | CWE-922 | A02:2025 | 7.5 | ESLint rule documentation for no-jwt-in-storage | ๐ผ | | | ๐ก | |
| no-missing-cors-check | | | | ESLint rule documentation for no-missing-cors-check | | | | | |
| no-missing-csrf-protection | | | | ESLint rule documentation for no-missing-csrf-protection | | | | | |
| no-missing-security-headers | | | | ESLint rule documentation for no-missing-security-headers | | | | | |
| no-password-in-url | | | | ESLint rule documentation for no-password-in-url | | | | | |
| no-permissive-cors | | | | ESLint rule documentation for no-permissive-cors | | | | | |
| no-postmessage-innerhtml | CWE-79 | A03:2025 | 6.1 | ESLint rule documentation for no-postmessage-innerhtml | ๐ผ | | | | |
| no-postmessage-wildcard-origin | CWE-346 | A01:2025 | 8.8 | ESLint rule documentation for no-postmessage-wildcard-origin | ๐ผ | | | | |
| no-sensitive-cookie-js | CWE-1004 | A02:2025 | 5.3 | ESLint rule documentation for no-sensitive-cookie-js | ๐ผ | | | ๐ก | |
| no-sensitive-data-in-analytics | | | | ESLint rule documentation for no-sensitive-data-in-analytics | | | | | |
| no-sensitive-data-in-cache | | | | ESLint rule documentation for no-sensitive-data-in-cache | | | | | |
| no-sensitive-indexeddb | CWE-922 | A02:2025 | 7.5 | ESLint rule documentation for no-sensitive-indexeddb | ๐ผ | | | ๐ก | |
| no-sensitive-localstorage | CWE-922 | A02:2025 | 7.5 | ESLint rule documentation for no-sensitive-localstorage | ๐ผ | | | ๐ก | |
| no-sensitive-sessionstorage | CWE-922 | A02:2025 | 7.5 | ESLint rule documentation for no-sensitive-sessionstorage | ๐ผ | | | ๐ก | |
| no-tracking-without-consent | | | | ESLint rule documentation for no-tracking-without-consent | | | | | |
| no-unencrypted-transmission | | | | ESLint rule documentation for no-unencrypted-transmission | | | | | |
| no-unescaped-url-parameter | | | | ESLint rule documentation for no-unescaped-url-parameter | | | | | |
| no-unsafe-eval-csp | CWE-95 | A03:2025 | 9.8 | ESLint rule documentation for no-unsafe-eval-csp | ๐ผ | | | ๐ก | |
| no-unsafe-inline-csp | CWE-79 | A03:2025 | 6.1 | ESLint rule documentation for no-unsafe-inline-csp | ๐ผ | | | ๐ก | |
| no-unvalidated-deeplinks | | | | ESLint rule documentation for no-unvalidated-deeplinks | | | | | |
| no-websocket-eval | CWE-95 | A03:2025 | 9.8 | ESLint rule documentation for no-websocket-eval | ๐ผ | | | ๐ก | |
| no-websocket-innerhtml | CWE-79 | A03:2025 | 6.1 | ESLint rule documentation for no-websocket-innerhtml | ๐ผ | | | ๐ก | |
| no-worker-message-innerhtml | CWE-79 | A03:2025 | 6.1 | ESLint rule documentation for no-worker-message-innerhtml | ๐ผ | | | | |
| require-blob-url-revocation | CWE-401 | A04:2025 | 5.3 | ESLint rule documentation for require-blob-url-revocation | ๐ผ | โ ๏ธ | | ๐ก | |
| require-cookie-secure-attrs | CWE-614 | A05:2025 | 5.3 | ESLint rule documentation for require-cookie-secure-attrs | ๐ผ | | | | ๐ซ |
| require-csp-headers | | | | ESLint rule documentation for require-csp-headers | | | | | |
| require-https-only | | | | ESLint rule documentation for require-https-only | | | | | |
| require-mime-type-validation | | | | ESLint rule documentation for require-mime-type-validation | | | | | |
| require-postmessage-origin-check | CWE-346 | A01:2025 | 8.8 | ESLint rule documentation for require-postmessage-origin-check | ๐ผ | | | | |
| require-url-validation | | | | ESLint rule documentation for require-url-validation | | | | | |
| require-websocket-wss | CWE-319 | A02:2025 | 7.5 | ESLint rule documentation for require-websocket-wss | ๐ผ | | | ๐ก | ๐ซ |
๐ Related ESLint Plugins
Part of the Interlace ESLint Ecosystem โ AI-native security plugins with LLM-optimized error messages:
| Plugin | Downloads | Description |
| :--- | :---: | :--- |
|
eslint-plugin-secure-coding |  | General security rules & OWASP guidelines. |
| eslint-plugin-pg |  | PostgreSQL security & best practices. |
| eslint-plugin-crypto |  | NodeJS Cryptography security rules. |
| eslint-plugin-jwt |  | JWT security & best practices. |
| eslint-plugin-browser-security |  | Browser-specific security & XSS prevention. |
| eslint-plugin-express-security |  | Express.js security hardening rules. |
| eslint-plugin-lambda-security |  | AWS Lambda security best practices. |
| eslint-plugin-nestjs-security |  | NestJS security rules & patterns. |
| eslint-plugin-mongodb-security |  | MongoDB security best practices. |
| eslint-plugin-vercel-ai-security |  | Vercel AI SDK security hardening. |
| eslint-plugin-import-next` |  | Next-gen import sorting & architecture. |MIT ยฉ Ofri Peretz