Vulnerability Report

CVE-2026-1527

Title: Undici HTTP Header Injection via CRLF in Upgrade Option

Other

Proof Of Concept

No public PoC currently indexed for CVE-2026-1527.

CWE Category CWE-93
Published Date Mar 12, 2026
Modified Date Mar 20, 2026
Exploit Status Not Found
Score 4.6 CVSS v3.1
Exploit Probability (EPSS)
0.01%

Vulnerability Summary

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` }

Impacted Vendors

N
nodejs 1

Reference Links

https://cna.openjsf.org/security-advisories.html https://github.com/nodejs/undici/security/advisories/GHSA-4992-7rv2-5pvq https://hackerone.com/reports/3487198
CVSS v3.1
Source Entity ce714d77-add3-4f53-aff5-83d477b104bb
Severity MEDIUM
4.6
Attack Vector
NETWORK
Complexity
LOW
Privileges
N/A
Interaction
REQUIRED
Confidentiality
N/A
Integrity
N/A
Availability
N/A
Scope
UNCHANGED
RAW VECTOR CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Associated Attack Patterns (CAPEC)

Total: Patterns

CVE-2026-1527 Exploits & PoCs (Proof Of Concept)

No public PoCs found in our database for this CVE.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

MODIFIED

Vulnerability data updated via NVD.

Attack Vector Matrix

Access Vector NETWORK
Complexity LOW
Privileges N/A
Interaction REQUIRED
CVSS Vector String CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Affected Stack

No specific products linked.