ClojureWasm (cljw) is a Clojure runtime with a WebAssembly FFI: it can load and execute untrusted .wasm bytecode in the same process as the host (through the embedded zwasm engine), and — in embeddings like the public playground — it evaluates untrusted Clojure source in-process. Memory safety and sandbox integrity are therefore first-class concerns, and we take reports seriously.

ClojureWasm is currently pre-1.0 (1.0.0-rc.* / 1.0.0-alpha.*). Security fixes land on the main branch and the newest pre-release tag.

Please do not open a public issue or Discussion for security problems.

Report privately via GitHub's Private Vulnerability Reporting (the "Report a vulnerability" button under the repository's Security tab). If that is unavailable to you, open a minimal public Discussion asking a maintainer to reach out — without any exploit detail — and mention @chaploud.

Please include, where possible:

• affected version / commit and target (aarch64-macos, x86_64-linux) and execution mode (interpreter / JIT / AOT for the Wasm FFI);
• a minimal reproducer — a .clj expression, or a .wasm / .wat module and the exact CLI / embedding call;
• the observed impact (host memory corruption, Wasm sandbox escape, WASI capability bypass, denial of service, etc.).

We aim to acknowledge a report within a few days. Because this is a small, resource-limited project, please allow reasonable time for a fix before any public disclosure.

In scope: host memory corruption from a malformed or adversarial .wasm module, Wasm sandbox / WASI-capability escapes, JIT code-generation bugs with a security impact, and memory-safety faults in the Zig runtime reachable from ordinary Clojure input.

Out of scope: behaviour of untrusted guest code that stays within the Wasm sandbox, resource exhaustion by trusted local scripts you run yourself, and misuse of the embedding API in ways the documentation warns against.