Report privately through GitHub Security Advisories. That opens a channel visible only to you and the maintainers.

Do not open a public issue for a suspected vulnerability. A public report on a compiler is a public report on everything it has compiled.

Include what you would want if you were fixing it: the DSDL or the input that triggers it, the tool and version (dsdlc --version), the platform, and what you observed. A reproducer beats a description.

This is a pre-1.0 project maintained by volunteers, so expect an acknowledgement within a week rather than within a day. If a report goes unacknowledged for two weeks, escalate on the OpenCyphal forum without describing the issue, and someone will find the report.

The latest release. Fixes land on main and go out in the next release; there are no maintenance branches to back-port to.

The interesting surface of a DSDL compiler is that it reads files it did not write and emits code somebody else will run.

In scope

• The frontend reading untrusted DSDL. A definition that causes memory corruption, an unbounded allocation, or a crash that is not a diagnostic. Malformed input must produce an error, not a signal.
• Generated serialisation code. A decoder that reads outside its buffer, or accepts a frame it should reject, on malformed or hostile wire data. This is the highest-severity class here: the defect ships to every consumer of the generated code rather than staying in the compiler.
• dsdld. It reads LSP over stdio, opens files by client-supplied path, and loads lint plugins with dlopen. Path traversal outside the configured roots, or plugin loading that can be steered by a document, is in scope.
• The release artifacts. A .deb or tarball whose contents do not match what the workflow built, or a build step that could be made to embed something the source does not contain.

Out of scope

• Defects in the DSDL corpus under submodules/, which is upstream — report those to the project that owns it.
• Defects in the CI toolshed image, likewise upstream.
• Running dsdlc on DSDL you do not trust and getting code you do not trust. Generating code is executing the definitions' intent; a definition that declares a 64 KiB array gets one. Trust boundaries belong around the definitions you compile.
• Resource exhaustion from deliberately pathological input, unless it escapes the bounds the compiler states — nesting depth is capped at 128, and a definition exceeding it is a diagnostic.

Release artifacts carry a provenance attestation and a CycloneDX SBOM recording the exact source commit and the LLVM revision linked. The LLVM the tools link is built by this repository from a revision pinned in packaging/toolchain/llvm.pin, rather than taken from a distribution, so what went into a binary is answerable from the tree that produced it. See docs/reference/guarantees/supply-chain.md.