CVE-2022-35948: CRLF Injection in Nodejs ‘undici’ via Content-Type

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2022-08-15 · updated 2026-06-17
Weakness: CWE-74

Description

undici is an HTTP/1.1 client, written from scratch for Node.js.`=< undici@5.8.0` users are vulnerable to _CRLF Injection_ on headers when using unsanitized input as request headers, more specifically, inside the `content-type` header. Example: ``` import { request } from 'undici' const unsanitizedContentTypeInput = 'application/json\r\n\r\nGET /foo2 HTTP/1.1' await request('http://localhost:3000, { method: 'GET', headers: { 'content-type': unsanitizedContentTypeInput }, }) ``` The above snippet will perform two requests in a single `request` API call: 1) `http://localhost:3000/` 2) `http://localhost:3000/foo2` This issue was patched in Undici v5.8.1. Sanitize input when sending content-type headers using user input as a workaround.

Affected products

undici: before 5.8.2 — fixed in 5.8.2
Npm Undici: before 5.8.2 — fixed in 5.8.2

How to fix

Upgrade to a fixed version: undici 5.8.2; Npm Undici 5.8.2. Check the vendor advisory for mitigations.

References

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