Security audit

Next.js 15 Best Practices

Security checks for vulnerabilities and agentic risk

Overview

This is a mostly coherent Next.js guidance skill, but its migration guide tells agents/users to run mutable canary/latest package commands that execute external code without pinning or containment guidance.

Review the migration commands before use. Prefer pinned, reviewed versions of Next.js, React, and `@next/codemod`, run codemods in a clean branch or disposable environment, and inspect generated changes before merging. The rest of the skill is ordinary Next.js guidance.

A.I.G

Vulnerability Patterns

Insecure DependenciesIntroduces malicious components through unsafe dependency sources
Skill Instruction HijackingAlters the agent's session goals or safety constraints when the skill loads
Agent Memory PoisoningWrites attacker-controlled rules into memory that affect later sessions
Remote Payload Retrieval and ExecutionFetches external code whose behavior can change after review
Embedded Malicious CodeShips malicious scripts inside the skill and executes them locally

Findings (1)

T08 · Insecure Dependencies

Warning

Location: references/migration-config.md:6
Finding: Unpinned Package Retrieval and Execution During Migration
Content: View full analysis
Remediation: View remediation

SkillSpector

Vulnerability Patterns

Data ExfiltrationExternal Transmission, Env Variable Harvesting, File System Enumeration
Privilege EscalationExcessive Permissions, Sudo/Root Execution, Credential Access
Supply ChainUnpinned Dependencies, External Script Fetching, Obfuscated Code
Prompt InjectionInstruction Override, Hidden Instructions, Exfiltration Commands
Excessive AgencyUnrestricted Tool Access, Autonomous Decision Making, Scope Creep

Findings (3)

Credential Access

High

Category: Privilege Escalation
Confidence: 60% confidence
Finding: Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
Content: Scanner excerpt · references/migration-config.md (reported line 69)May include surrounding context.
Environment Variables

bash
# .env.local DATABASE_URL="postgresql://..." NEXT_PUBLIC_API_URL="https://api.example.com" # exposed to browser

External Transmission

Medium

Category: Data Exfiltration
Confidence: 50% confidence
Finding: Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.
Content: Scanner excerpt · SKILL.md (reported line 71)May include surrounding context.
md
} // fetch with cache control const data = await fetch("https://api.example.com/data", { next: { revalidate: 60 }, // ISR: revalidate every 60s // cache: "no-store" // always fresh // cache: "force-cache" // static, until manual revalidation

Rp1