CVE-2026-48932CWE-444

CVE-2026-48932

Low · published September 1, 2026

CVSS v3.0
3.7
EPSS
0%
Percentile
18.3
In the wild
Unconfirmed
What it is

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**.

The record
Technical detail
CVSS v3.0
3.7 · LOW
Vector
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00271 · 18.3th percentile
Weakness
CWE-444 · Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
Published
2026-09-01T07:16Z
References (1)
https://hackerone.com/reports/3564941 · [email protected]
EPSS history
Timeline
  • 02 SEP 03:37Z
    EPSS moved — → 0%
    epss
  • 01 SEP 02:08Z
    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…
    cvelistv5