CVE-2026-1527
Published: March 13, 2026Last modified: June 16, 2026
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` }
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 4.6 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | REQUIRED |
| Scope | UNCHANGED |
| Confidentiality | LOW |
| Integrity impact | LOW |
| Availability impact | NONE |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:L/I:L/A:N |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | nodejs | Fixed (20.20.2-r0) |
| 25 LTS | nodejs | Fixed (22.22.2-r0) | |
| Stream | nodejs | Fixed (24.16.0-r0) | |
| Hardened Containers | 23 LTS | nodejs | Fixed (20.20.2-r0) |
| 25 LTS | nodejs | Fixed (22.22.2-r0) | |
| Stream | nodejs | Fixed (24.16.0-r0) |