CVE-2026-1527
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` }
How to fix
- nodejs undici6.24.0, 7.24.0 or later
- undici6.24.0, 7.24.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| nodejs undici | v < 6.24.0, 7.0.0 ≤ v < 7.24.0 | 6.24.0, 7.24.0 |
| undicinpm | v < 6.24.0, 7.0.0 ≤ v < 7.24.0 | 6.24.0, 7.24.0 |
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