A flaw in Node.js HTTP client can cause a request desynchronization for Node.js-based forwarding proxies that rebuild outbound headers from the visible IncomingMessage headers while piping the original body to a reused backend connection.
Node.js can omit headers beyond maxHeadersCount / maxHeaderPairs from req.headers, req.rawHeaders, and req.headersDistinct, while still using those omitted headers internally for HTTP message framing. In particular, Content-Length can be hidden from userland while the request body is still delivered.
This vulnerability affects all supported release lines: Node.js 22, Node.js 24, and Node.js 26.
{
"severity": "Low",
"cpes": [
"cpe:2.3:a:nodejs:node.js:*:*:*:*:*:*:*:*"
]
}