CVE-2026-58044
LowCVSS 3.7Exploitation Probability (EPSS)
Low risk20th percentile - higher than 20% of all known CVEs
Summary
A flaw in the Node.js HTTP client can cause 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, particularly hiding `Content-Length` from userland while the request body is still delivered.
Risk Assessment
The risk is that Node.js-based proxies may send requests to backends with incorrect or missing headers, leading to request desynchronization, potentially enabling request smuggling attacks or manipulation of request content.
Recommendation
Immediately update Node.js to the latest patched version for all affected release lines (22, 24, 26) and monitor security advisories. Additionally, if possible, restrict the use of Node.js-based proxies until patches are applied.
Original NVD description (English source)
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**.