Skip to content

Security: Fengrru/nexus-runtime

Security

SECURITY.md

Security Policy

Supported Versions

Version Supported
1.0.x

Reporting a Vulnerability

Do not open a public issue. Instead, send a detailed report to:

Include:

  • Description of the vulnerability
  • Steps to reproduce
  • Affected components and versions
  • Potential impact

You will receive an acknowledgment within 48 hours and a timeline for resolution within 5 business days.

Security Model

Nexus Runtime enforces several security boundaries:

Worker Isolation

  • Workers communicate exclusively via JSON-RPC 2.0 over stdio — no network sockets, no shared memory
  • Each worker receives HMAC-SHA256 capability tokens scoped to the specific task
  • Workers cannot access the LLM API directly; all calls are proxied through the Kernel with budget enforcement

Sandbox Tiers

Tier Description Enforcement
untrusted No filesystem access, no network, no subprocesses WASM sandbox with fuel metering + path traversal guard
readonly Read-only access to specified paths Capability token scope + filesystem path validation
sandboxed Read-write within a chroot-like boundary Path traversal protection + sandbox directory
full Reserved for kernel-internal operations Signature verification required

Side-Effect Safety

All external actions are classified into four categories with distinct recovery strategies:

Class Examples Recovery Strategy
Pure read_file, grep, calculate Safe to replay
Idempotent upsert, write_file Replay with idempotency key
Reversible edit_file, patch Compensate then replay
Irreversible send_email, git_push, deploy Query external state before action

Data Integrity

  • All artifacts are content-addressed with BLAKE3 hashes
  • Event payloads carry integrity hashes verified on recovery
  • Session state transitions are cryptographically linked via causal vectors
  • LLM API keys are zeroized after use (Zeroizing<String>)

Dependency Auditing

  • cargo-deny runs on every CI push checking for known vulnerabilities (RUSTSEC advisories)
  • License compliance enforced for all transitive dependencies
  • Multiple crate versions are denied to prevent dependency confusion

Responsible Disclosure

We follow the CVD (Coordinated Vulnerability Disclosure) process. Critical vulnerabilities will be addressed with an emergency patch release.

There aren't any published security advisories