CVE-2026-71554

5.3 Moyenne

Publiée le 07/08/2026 à 00:18 · Modifiée le 18/09/2026 à 22:09 · Analyse NVD reportée · Source : security-advisories@github.com

Description

h2 is a pure-Python implementation of a HTTP/2 protocol stack. Versions up to and including 4.4.0 accept request header blocks containing more than one Host header, and forward every Host header to the consuming application. Where the consumer downgrades HTTP/2 to HTTP/1.1, the resulting request carries two Host header lines, providing a request smuggling primitive. This issue is fixed in version 4.4.1.

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Produits concernés

python-hyper h2

Scores CVSS

Version	Score	Source	Vecteur
3.1	5.3 Moyenne	security-advisories@github.com	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L`

Faiblesses (CWE)

CWE-444

Références

https://github.com/python-hyper/h2/commit/292a40829feefda98c8509dcdbbb4a57af9bd6a6
https://github.com/python-hyper/h2/security/advisories/GHSA-6hr6-w5qg-qmwg

Ailleurs

NVD
CVE.org
CIRCL Vulnerability-Lookup
CERT-FR
GitHub Advisories