CVE-2026-1527

MEDIUM

4.6

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` }

CVE Details

CVSS v3.1 Score4.6

SeverityMEDIUM

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredLOW

User InteractionREQUIRED

Published3/12/2026

Last Modified3/20/2026

Sourcenvd

Honeypot Sightings0

Affected Products

nodejs:undici

Weaknesses (CWE)

CWE-93

References

https://cna.openjsf.org/security-advisories.html(ce714d77-add3-4f53-aff5-83d477b104bb)

https://github.com/nodejs/undici/security/advisories/GHSA-4992-7rv2-5pvq(ce714d77-add3-4f53-aff5-83d477b104bb)

https://hackerone.com/reports/3487198(ce714d77-add3-4f53-aff5-83d477b104bb)

IOC Correlations

No correlations recorded

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