CVE detail

CVE-2021-22959 — CVE-2021-22959

Published 2021-11-15 · Modified 2026-06-17 · Vendor llhttp · Product llhttp · Source nvd

MEDIUM

severity

CVSS-derived band

6.5

CVSS v3

0–10 scale

0.0294

EPSS probability

exploitation probability, 30d

86.0%

EPSS percentile

percentile vs all CVEs

NOT LISTED

CISA KEV

known exploited catalog

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.

Remediation

No vendor-published fix data in our corpus for this CVE. Check the references below or the vendor's PSIRT / security advisories page.

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.