GHSA-wqvq-jvpq-h66f: Nodemailer jsonTransport bypasses disableFileAccess and disableUrlAccess during message normalization

Nodemailer’s disableFileAccess and disableUrlAccess options are intended to prevent message content and attachments from reading local files or fetching URLs. The normal MIME streaming path enforces those options in MimeNode._getStream(). However, jsonTransport serializes messages by calling mail.normalize(), which resolves html, text, alternatives, calendar events, and attachments through shared.resolveContent() before MIME generation. shared.resolveContent() reads local files and fetches HTTP(S) URLs directly, without receiving or checking disableFileAccess or disableUrlAccess.

As a result, applications that use jsonTransport as a safe serializer or queue payload generator while relying on disableFileAccess / disableUrlAccess can still be made to read local files into the generated JSON output or make outbound HTTP requests when an attacker controls message content fields such as attachment path or text.href.

The same missing-enforcement root cause is also reachable before normal streaming when attachDataUrls causes _convertDataImages() to call mail.resolveContent(mail.data, 'html', ...); this should be fixed with the same access-control check.