CVE-2026-1527

Name	CVE-2026-1527
Description	ImpactWhen an application passes user-controlled input to the upgrade option of client.request(), an attacker can inject CRLF sequences (\r\n) to: * Inject arbitrary HTTP headers * Terminate the HTTP request prematurely and smuggle raw data to non-HTTP services (Redis, Memcached, Elasticsearch) The vulnerability exists because undici writes the upgrade value directly to the socket without validating for invalid header characters: // lib/dispatcher/client-h1.js:1121 if (upgrade) { header += `connection: upgrade\r\nupgrade: ${upgrade}\r\n` }
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1130882

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
node-undici (PTS)	bookworm	5.15.0+dfsg1+~cs20.10.9.3-1+deb12u4	vulnerable
	bookworm (security)	5.15.0+dfsg1+~cs20.10.9.3-1+deb12u3	vulnerable
	trixie	7.3.0+dfsg1+~cs24.12.11-1	vulnerable
	forky	7.18.2+dfsg+~cs3.2.0-1	vulnerable
	sid	7.24.6+dfsg+~cs3.2.0-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
node-undici	source	(unstable)	7.24.5+dfsg+~cs3.2.0-1			1130882

Notes

https://github.com/nodejs/undici/security/advisories/GHSA-4992-7rv2-5pvq
https://github.com/nodejs/undici/commit/e43e898603dd5e0c14a75b08b83257598d664a39 (v6.24.0)
https://github.com/nodejs/undici/commit/77594f923cef4c27ee0bad365e7b4c44a199edae (v7.24.0)