VULNERABILITY INTELLIGENCE

CVE-2021-22959

CVSS score6.5 MEDIUM

EPSS probability3.16%

CISA KEVNot currently listed

Published2021-11-15

Last modified2026-06-17

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

Description

The parser in accepts requests with a space (SP) right after the header name before the colon. This can lead to HTTP Request Smuggling (HRS) in llhttp < v2.1.4 and < v6.0.6.

Weakness classification

support@hackerone.com: CWE-444
nvd@nist.gov: CWE-444

Primary references

support@hackerone.com — Exploit, Issue Tracking, Third Party Advisory
support@hackerone.com — Mailing List, Third Party Advisory
support@hackerone.com — Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Exploit, Issue Tracking, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108 — Patch, Third Party Advisory