CRLF Injection Affecting nodejs20-devel package, versions <1:20.20.1-1.amzn2023.0.3


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.26% (17th percentile)

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  • Snyk IDSNYK-AMZN2023-NODEJS20DEVEL-15922100
  • published7 Apr 2026
  • disclosed12 Mar 2026

Introduced: 12 Mar 2026

CVE-2026-1527  (opens in a new tab)
CWE-93  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 nodejs20-devel to version 1:20.20.1-1.amzn2023.0.3 or higher.
This issue was patched in ALAS2023-2026-1524.

NVD Description

Note: Versions mentioned in the description apply only to the upstream nodejs20-devel package and not the nodejs20-devel package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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 Base Scores

version 3.1