react-doctor/mdx-ssr-execution-risk

Compiling untrusted MDX with the full pipeline runs attacker-supplied JSX and expressions on your server, which can lead to code execution.

Validation prompt

Confirm the detector match and collect the required evidence before deciding whether an edit is warranted.

Fires when an MDX library surface (@mdx-js/mdx, next-mdx-remote, or MDXRemote/compileMDX/evaluateMdx) is followed within ~700 chars by an untrusted-source or dangerous-flag marker: repo/customer/tenant/user-content|markdown|mdx|input|provided|generated|submitted/untrusted/searchParams/req./request./fetch(/prisma./db./database/rehypeRaw/allowDangerousHtml. Comments are stripped first.

Suppress when: the file compiles its own first-party, build-time MDX (docs/blog content from the repo's own content/ directory) with no attacker-controlled source: generic library usage co-occurring with a word like content is not itself a vulnerability; a bare evaluate/compile not tied to an MDX surface is also excluded.

Evidence boundary

The diagnostic proves only that the detector’s modeled source pattern matched. It does not prove runtime impact, product intent, rendered failure, or that one remediation is correct.

Establish the environment, repository policy, exceptions, and required rendered or runtime evidence before deciding the occurrence.

Record one outcome:

• Confirmed failure: The required evidence establishes the violation.
• Rejected: A documented exception or false-positive predicate applies.
• Needs evidence: Named evidence can still be collected.
• Unavailable: Required evidence cannot be collected in this run.
• Waived with evidence: An authorized, scoped exception applies to an established failure.
• Observation: The review records an optional tradeoff without claiming a defect.

A waiver records its scope, authority, evidence, and review condition. It is not a pass or false positive.

Default severity is registry metadata. Use the occurrence’s JSON severity after repository configuration when ordering real findings.

Fix prompt

Apply this candidate correction only after the required evidence confirms the risk.

Never compile or evaluate attacker-controlled MDX with the full pipeline. For untrusted content, use a constrained compiler: disable JSX, expressions, and raw HTML (do not enable rehype-raw or allowDangerousHtml), render through a sandbox with an allowlisted component set, and prefer plain Markdown that cannot run code. Do not cache one tenant's rendered output where another tenant can read it.

Repository-wide copy prompt

Use this repository-wide prompt only after validating each occurrence. For one occurrence, use the guidance above.