For stream request bodies, maxBodyLength is bypassed when maxRedirects is set to 0 (native http/https transport path). Oversized streamed uploads are sent fully even when the caller sets strict body limits.
Relevant flow in lib/adapters/http.js: - 556-564: maxBodyLength check applies only to buffered/non-stream data. - 681-682: maxRedirects === 0 selects native http/https transport. - 694-699: options.maxBodyLength is set, but native transport does not enforce it. - 925-945: stream is piped directly to socket (data.pipe(req)) with no Axios byte counting.
This creates a path-specific bypass for streamed uploads.
### PoC
Environment:
Node v24.2.0
Steps:
Send a 2 MiB Readable stream with: - adapter: 'http' - maxBodyLength: 1024 - maxRedirects: 0
Observed:
Request succeeds; server reports received: 2097152.
Control checks:
Buffered body with maxRedirects: 0: rejected with ERRBADREQUEST.
Type: DoS / uncontrolled upstream upload / resource exhaustion. Impacted: Node.js services using streamed request bodies with maxBodyLength expecting hard enforcement, especially when following Axios guidance to use maxRedirects: 0 for streams.
{
"github_reviewed_at": "2026-05-05T00:33:25Z",
"nvd_published_at": "2026-04-24T18:16:30Z",
"cwe_ids": [
"CWE-770"
],
"severity": "MODERATE",
"github_reviewed": true
}