CVE-2026-123875: Node.js is vulnerable to an HTTP/2 denial of service via a NULL pointer dereference when a respondWithFile() download is cancelled

A NULL pointer dereference in Node.js HTTP/2 lets an unauthenticated client crash the server, over both TLS and cleartext, by cancelling file downloads. When the server serves a file with stream.respondWithFile() or stream.respondWithFD() and the client cancels the request, a StreamPipe used for the transfer is torn down in an order that leaves a NULL pointer which is then dereferenced, aborting the process. No crafted frames are needed, and a handful of cancelled requests against a default file-serving handler is enough. This vulnerability affects Node.js 26.x, 24.x, and 22.x.