https://vulnerability.circl.lu/rss/recent/all/10 Most recent entries from all 2026-09-29T18:03:27.343691+00:00 Vulnerability-Lookup info@circl.lu python-feedgen Contains only the most 10 recent entries. https://vulnerability.circl.lu/vuln/cve-2025-57804 CVE-2025-57804 — h2 allows HTTP Request Smuggling due to illegal characters in headers 2026-09-29T18:03:29.004927+00:00

Affected: python-hyper h2

h2 is a pure-Python implementation of a HTTP/2 protocol stack. Prior to version 4.3.0, an HTTP/2 request splitting vulnerability allows attackers to perform request smuggling attacks by injecting CRLF characters into headers. This occurs when servers downgrade HTTP/2 requests to HTTP/1.1 without properly validating header names/values, enabling attackers to manipulate request boundaries and bypass security controls. This issue has been patched in version 4.3.0.

 https://vulnerability.circl.lu/vuln/ghsa-847f-9342-265h GHSA-847f-9342-265h — h2 allows HTTP Request Smuggling due to illegal characters in headers 2026-09-29T18:03:29.005051+00:00

Affected: PyPI: h2

### Summary

HTTP/2 request splitting vulnerability allows attackers to perform request smuggling attacks by injecting CRLF characters into headers. This occurs when servers downgrade HTTP/2 requests to HTTP/1.1 without properly validating header names/values, enabling attackers to manipulate request boundaries and bypass security controls.

 https://vulnerability.circl.lu/vuln/pysec-2026-1435 PYSEC-2026-1435 — h2 allows HTTP Request Smuggling due to illegal characters in headers 2026-09-29T18:03:29.005100+00:00

Affected: PyPI: h2

### Summary

HTTP/2 request splitting vulnerability allows attackers to perform request smuggling attacks by injecting CRLF characters into headers. This occurs when servers downgrade HTTP/2 requests to HTTP/1.1 without properly validating header names/values, enabling attackers to manipulate request boundaries and bypass security controls.