https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-10-03T08:33:12.475152+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/cve-2026-71554 CVE-2026-71554 — h2: Duplicate Host header could facilitate request smuggling 2026-10-03T08:33:12.477672+00:00

Affected: python-hyper h2

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.