Security fixes are released for the latest minor version line. Older lines are not patched — upgrade to the latest release to receive fixes.

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

Report privately through GitHub's private vulnerability reporting (Security → Report a vulnerability). If that is unavailable to you, open a regular issue that says only that you have a security report and asks for a private channel — no details.

Please include, as far as you can:

• the affected version, plus your Python and wasmtime versions;
• a description of the issue and its impact;
• steps or a minimal policy/input that reproduces it;
• any suggested fix.

We aim to acknowledge a report within 3 business days and to keep you updated as we work on a fix. We will credit you in the advisory unless you ask us not to.

This SDK evaluates OPA policies compiled to WebAssembly, in-process, on the wasmtime runtime. Issues that are in scope include:

• escaping the Wasm sandbox, or reaching host resources from guest policy code;
• bypassing the configured resource limits (max_memory_pages, eval_timeout_seconds, input/data/result byte caps) to hang or exhaust the host;
• returning an incorrect policy decision — for example a decision that reads as "allow" when the policy denies;
• leaking one evaluation's data or input into another across the instance pool;
• memory-safety or lifecycle faults in the native Store/Memory/Instance handling.

Out of scope:

• vulnerabilities in wasmtime or OPA themselves — please report those upstream (we will happily help you route a report);
• insecure Rego written by a policy author, which is a property of the policy and not of this SDK;
• host builtins registered by a consumer via register_builtin, which run as ordinary Python with the host's privileges. Bounding what a builtin can do, and enforcing its own timeout, is the caller's responsibility — this is documented behavior, not a vulnerability.

eval_timeout_seconds bounds guest Wasm execution using Wasmtime epoch interruption. It does not interrupt a blocking Python host builtin. A builtin that blocks indefinitely will hold its instance indefinitely; that is expected and documented in docs/thread_safety.md.