The llhttp parser in the http module in Node v20.2.0 does not strictly use the CRLF sequence to delimit HTTP requests.

Summary

The llhttp parser in the http module in Node v20.2.0 does not strictly use the CRLF sequence to delimit HTTP requests. This can lead to HTTP Request Smuggling (HRS). The CR character (without LF) is sufficient to delimit HTTP header fields in the llhttp parser. According to RFC7230 section 3, only the CRLF sequence should delimit each header-field. This impacts all Node.js active versions: v16, v18, and, v20

Timeline

1. Jun 30, 2023, 11:39 PM UTCCVE published
2. Oct 8, 2026, 9:06 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: yes · Technical impact: partial

3. Oct 8, 2026, 9:13 PM UTCRecord last updated

Affected versions

• NodeJS Node

  From 4.0 · fixed in 4.*; From 5.0 · fixed in 5.*; From 6.0 · fixed in 6.*; From 7.0 · fixed in 7.*; From 8.0 · fixed in 8.*; From 9.0 · fixed in 9.*; From 10.0 · fixed in 10.*; From 11.0 · fixed in 11.*; From 12.0 · fixed in 12.*; From 13.0 · fixed in 13.*; From 14.0 · fixed in 14.*; From 15.0 · fixed in 15.*; From 16.0 · fixed in 16.20.1; From 17.0 · fixed in 17.*; From 18.0 · fixed in 18.16.1; From 19.0 · fixed in 19.*; From 20.0 · fixed in 20.3.1

• nodeBitnami

  From 16.0.0 · fixed in 16.20.1; From 18.0.0 · fixed in 18.16.1; From 20.0.0 · fixed in 20.3.1

• node-minBitnami

  From 16.0.0 · fixed in 16.20.1; From 18.0.0 · fixed in 18.16.1; From 20.0.0 · fixed in 20.3.1

• llhttpnpm

  fixed in 8.1.1

References 9