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Security: dean0x/mdscript

Security

Report a vulnerability

SECURITY.md

Security Policy

Reporting a vulnerability

Please do not report security vulnerabilities through public GitHub issues, discussions, or pull requests.

Report vulnerabilities privately through GitHub's private vulnerability reporting. This routes the report to the maintainers privately and lets us collaborate on a fix and coordinated disclosure.

Please include, where possible:

  • A description of the issue and its impact
  • The affected component (CLI, mds-core, WASM, native addon, a bundler plugin)
  • Steps to reproduce, or a minimal .mds template / input that triggers it
  • The version (crate or npm package) and your platform

We aim to acknowledge reports within a few days and will keep you updated as we investigate.

Supported versions

MDS is pre-1.0. Security fixes are applied to the latest released minor series only; please upgrade to the newest release before reporting.

Version Supported
0.1.x ✅
< 0.1.0 ❌

Security model & built-in controls

MDS treats template sources, imported modules, and runtime variables as untrusted input. The compiler enforces several defense-in-depth controls:

Filesystem boundary (crates/mds-core/src/fs.rs, resolver.rs)

  • Path-traversal prevention: import paths and the output_dir config value are rejected if they escape the project root (.. traversal).
  • Symlink rejection: symlinked import paths are refused. Resolution is written to be TOCTOU-safe (the resolved target is validated, not just the pre-resolution path).
  • Null-byte rejection: paths containing NUL bytes are rejected at the API boundary rather than being passed to the OS.
  • Non-UTF-8 paths are rejected at the public API boundary with an explicit error instead of producing corrupted output.

Resource limits

Limit Value Location
Max file size 10 MB per source file limits.rs (MAX_FILE_SIZE)
Max mds.json size 1 MB mds-cli/src/main.rs (MAX_CONFIG_SIZE)
Max call depth 128 evaluator.rs (MAX_CALL_DEPTH)
Max iterations per loop 100,000 evaluator.rs (MAX_LOOP_ITERATIONS)
Max total iterations 1,000,000 evaluator.rs (MAX_TOTAL_ITERATIONS)
Max output size 50 MB evaluator.rs (MAX_OUTPUT_SIZE)
Max warnings 1,000 evaluator.rs (MAX_WARNINGS)
Max import depth 64 resolver.rs (MAX_IMPORT_DEPTH)
Max block nesting depth 64 limits.rs (MAX_NESTING_DEPTH)
Max @elseif branches per @if 256 limits.rs (MAX_ELSEIF_BRANCHES)
Max value (YAML/JSON) nesting depth 64 value.rs (MAX_VALUE_DEPTH)
Max dot-path segments 32 limits.rs (MAX_DOT_SEGMENTS)

These guard against adversarial input causing stack overflow, unbounded memory growth, or non-termination.

⚠️ The debug-panics feature must never ship enabled

mds-core, mds-wasm, and mds-napi expose an off-by-default debug-panics Cargo feature. It surfaces the raw Rust panic payload (as err.detail on mds::internal errors) to help diagnose unexpected panics during local development.

Never enable debug-panics in a published or production build. Panic messages can contain absolute filesystem paths and other internal details that should not be exposed to template authors or end users. All release builds and published artifacts are built with the feature disabled.

There aren't any published security advisories