CVE-2026-1527

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` }

CVSS v3 4.6 MEDIUM

4.6^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.1 / Impact : 2.5

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction REQUIRED

Confidentiality Impact LOW

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://cna.openjsf.org/security-advisories.html	Vendor Advisory
https://github.com/nodejs/undici/security/advisories/GHSA-4992-7rv2-5pvq	Mitigation Patch Vendor Advisory
https://hackerone.com/reports/3487198	Permissions Required

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:nodejs:undici::::::node.js::*
	cpe:2.3:a:nodejs:undici::::::node.js::*

History

No history.

Information

Published : 2026-03-12 21:16

Updated : 2026-03-20 15:49

NVD link : CVE-2026-1527

Mitre link : CVE-2026-1527

CVE.ORG link : CVE-2026-1527

JSON object : View

Products Affected

nodejs

undici

CWE

CWE-93

Improper Neutralization of CRLF Sequences ('CRLF Injection')

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