CVE-2026-48932

Severity: low (CVSS 3.7 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-01 · updated 2026-09-03
Weakness: CWE-444

Description

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**.

Affected products

Node.js: from 22.22.3 through 22.22.3; from 24.16.0 through 24.16.0; from 26.3.0 through 26.3.0

References

https://hackerone.com/reports/3564941

Get alerted when CVE-2026-48932 or the next vulnerability affects your stack