⭐ If this plugin caught a real bug for you, star the repo — it's the signal that keeps these rules maintained.

Description

This plugin provides Security validation for JSON Web Tokens (JWT) implementation (signing, verification).

• Why — a linter nobody reads protects nothing. We would rather miss a finding than spend your attention on one that was never real.
• How — evidence, not names. A rule fires on what the code does, resolved through the AST and ESLint's own scope analysis.
• What — every finding carries its fix, in prose for a human and as structured JSON for an agent. Security rules add a CWE mapping and, where assigned, a CVSS score.

That trade costs recall, and we measure it: methodology · results · a false positive is a bug.

Getting Started

• To check out the guide, visit eslint.interlace.tools. 📚

npm install eslint-plugin-jwt-security --save-dev

⚙️ Configuration Presets

| Preset | Description | | :------------ | :-------------------------------------------------------- | | recommended | Recommended preset - balanced security | | strict | Strict preset - maximum security (includes 2025 research) | | legacy | Legacy preset - migration mode | | all | All rules preset |

📚 Supported Libraries

| Library | npm | Downloads | Detection | | :------------- | :-------------------------------------------------------------------------------------------------------------------- | :--------------------------------------------------------------------------------------------------------------------------- | :------------------------------ | | jsonwebtoken | | | Signing, Verification, Decoding | | jose | | | Verification (Fix Suggestion) | | jwt-decode | | | Unsafe Decoding |

🤖 AI-Optimized Messages

Every rule uses formatLLMMessage for structured output:

🔒 CWE-347 OWASP:A02-Crypto CVSS:9.8 | Using alg:"none" bypasses signature verification
   Fix: Remove "none" and use RS256, ES256, or other secure algorithms
   https://nvd.nist.gov/vuln/detail/CVE-2022-23540

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.

By structuring errors with specific CWE codes, OWASP categories, and direct fix suggestions, this format allows AI coding assistants to autonomously identify, explain, and resolve security vulnerabilities with high confidence.

💡 What You Get

• 13 Security Rules - Algorithm attacks, replay prevention, claim validation
• 6 JWT Libraries - jsonwebtoken, jose, express-jwt, @nestjs/jwt, jwks-rsa, jwt-decode
• 2025 Research - "Back to the Future" replay attack prevention (LightSEC 2025)
• AI-Optimized - Structured messages for GitHub Copilot, Cursor, Claude assistance
• CWE References - Every rule maps to Common Weakness Enumeration

📦 Compatibility

| Package | Version | | :--- | :--- | | ESLint | ^8.40.0 \|\| ^9.0.0 \|\| ^10.0.0 | | Node.js | >=18.0.0 |

See the ESLint Version Support Policy — current ecosystem share data, the 20% gate, and the forward-looking exception that covers v10.

Rules

Legend

| Icon | Description | | :---: | :--- | | 💼 | Recommended: Included in the recommended preset. | | ⚠️ | Warns: Set to warn in recommended preset. | | 🔧 | Auto-fixable: Automatically fixable by the --fix CLI option. | | 💡 | Suggestions: Providing code suggestions in IDE. | | 🚫 | Deprecated: This rule is deprecated. | | 🟢 | Type-unaware: AST-only, runs in oxlint JS-plugin tier. | | 🟡 | Type-aware (refining): pure-AST primary path; types refine precision. | | 🟠 | Type-aware (graceful): requires TS program; silent without it. |

| Rule | CWE | OWASP | CVSS | Description | 🧠 | 💼 | ⚠️ | 🔧 | 💡 | 🚫 | | :--- | :---: | :---: | :---: | :--- | :---: | :---: | :---: | :---: | :---: | :---: | | no-algorithm-confusion | CWE-347 | | | This rule detects algorithm confusion attacks where symmetric algorithms (HS256, HS384, HS512) are used wit… | 🟢 | 💼 | | | | | | no-algorithm-none | CWE-347 | | | This rule detects attempts to use the none algorithm which completely bypasses JWT signature verification | 🟢 | 💼 | | | | | | no-decode-without-verify | CWE-345 | | | The rule provides LLM-optimized error messages (Compact 2-line format) with actionable security guidance: | 🟢 | 💼 | | | | | | no-hardcoded-secret | CWE-798 | | | The rule provides LLM-optimized error messages (Compact 2-line format) with actionable security guidance: | 🟢 | 💼 | | | | | | no-sensitive-payload | CWE-359 | | | JWT payloads are NOT encrypted, only base64-encoded | 🟢 | | ⚠️ | | | | | no-timestamp-manipulation | CWE-294 | | | This rule detects noTimestamp: true which disables automatic iat (issued at) claim generation | 🟢 | 💼 | | | | | | no-weak-secret | CWE-326 | | | The rule provides LLM-optimized error messages (Compact 2-line format) with actionable security guidance: | 🟢 | 💼 | | | | | | require-algorithm-whitelist | CWE-757 | | | This rule enforces explicit algorithm specification in verify() calls | 🟢 | 💼 | | | | | | require-audience-validation | CWE-287 | | | The rule provides LLM-optimized error messages (Compact 2-line format) with actionable security guidance: | 🟢 | | | | | | | require-expiration | CWE-613 | | | The rule provides LLM-optimized error messages (Compact 2-line format) with actionable security guidance: | 🟢 | 💼 | | | | | | require-issued-at | CWE-294 | | | This rule ensures tokens have the iat claim for freshness validation | 🟢 | | ⚠️ | | | | | require-issuer-validation | CWE-287 | | | The rule provides LLM-optimized error messages (Compact 2-line format) with actionable security guidance: | 🟢 | | | | | | | require-max-age | CWE-294 | | | This rule mandates maxAge in verify operations | 🟢 | | | | | |

🔗 Related ESLint Plugins

Part of the Interlace ESLint ecosystem — AI-native rules with LLM-optimized error messages:

Security

| Plugin | Downloads | Description | | :--- | :---: | :--- | | eslint-plugin-anthropic-security | | Anthropic SDK security. | | eslint-plugin-browser-security | | XSS, DOM security. | | eslint-plugin-drizzle-security | | Drizzle security. | | eslint-plugin-express-security | | Express middleware hardening. | | eslint-plugin-gemini-security | | Google Gemini SDK security. | | eslint-plugin-knex-security | | Knex security. | | eslint-plugin-lambda-security | | AWS Lambda hardening. | | eslint-plugin-mcp-sdk-security | | MCP SDK security. | | eslint-plugin-mongodb-security | | MongoDB injection. | | eslint-plugin-mysql-security | | MySQL security. | | eslint-plugin-nestjs-security | | NestJS framework hardening. | | eslint-plugin-node-security | | Server-side patterns. | | eslint-plugin-openai-security | | OpenAI SDK security. | | eslint-plugin-postgresql-security | | PostgreSQL security. | | eslint-plugin-prisma-security | | Prisma security. | | eslint-plugin-secure-coding | | Injection prevention. | | eslint-plugin-sequelize-security | | Sequelize ORM security. | | eslint-plugin-sqlite-security | | SQLite security. | | eslint-plugin-supabase-security | | Supabase security. | | eslint-plugin-typeorm-security | | TypeORM security. | | eslint-plugin-vercel-ai-security | | AI SDK security. |

Code quality

| Plugin | Downloads | Description | | :--- | :---: | :--- | | eslint-plugin-cli-floor | | CLI floor for commander, yargs and burgee. | | eslint-plugin-conventions | | Team-specific habits and styles. | | eslint-plugin-import-next | | Fast cycle + import-graph analysis. | | eslint-plugin-maintainability | | Cognitive load and clean-code patterns. | | eslint-plugin-modernization | | ESNext migration + syntax evolution. | | eslint-plugin-modularity | | Structural integrity and DDD patterns. | | eslint-plugin-operability | | Production readiness and resource health. | | eslint-plugin-react-a11y | | React accessibility / WCAG. | | eslint-plugin-react-features | | React best practices and optimization. | | eslint-plugin-reliability | | Runtime stability and error safety. |

⭐ Support & follow

If this plugin caught a real bug for you, star the repo — stars are the signal that keeps the Interlace ESLint ecosystem maintained — and follow the writeups on Dev.to for the benchmarks and security research behind these rules.

📄 License

MIT © Ofri Peretz