Synapse is pre-1.0. Only the latest released version on the current 0.x line receives security fixes. Upgrade before reporting an issue if you are on an older release.

Report privately — do not open a public issue.

Use GitHub Security Advisories ("Report a vulnerability" on the repository's Security tab). If you cannot use that, email dskrl@outlook.com.

Please include the Synapse version, your OS and Python version, and the smallest reproduction you can manage. Expect an initial response within a week.

Synapse indexes source code on the machine it runs on, so the boundaries worth attacking are narrow and worth stating explicitly:

• Local-first. Source code is never uploaded anywhere. There are no network calls in the index, watch, query, or MCP serving paths.
• Explicit downloads only. The single network operation is synapse grammars install, which fetches tree-sitter parser binaries on demand. Indexing loads only parsers already present in the local cache and reports a setup error instead of downloading implicitly.
• Local data. The SQLite index, watch state, and logs live under the workspace data directory and the user config directory. Nothing is written outside the workspace and those directories.
• Untrusted input. Indexed source files, .synapse/config.json, and MCP tool arguments are all untrusted input. Path traversal, writes outside the workspace, and code execution from parsing a file are in scope.

When reporting, say which of those boundaries your finding crosses — it makes triage much faster.

Out of scope: vulnerabilities in tree-sitter grammars themselves (report those upstream), and anything that requires an attacker to already have local code-execution as your user.