CVE-2025-57804

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.

CVSS

No CVSS.

References

Link	Resource
https://github.com/python-hyper/h2/commit/035e9899f95e3709af098f578bfc3cd302298e3a
https://github.com/python-hyper/h2/security/advisories/GHSA-847f-9342-265h
https://lists.debian.org/debian-lts-announce/2025/09/msg00004.html

Configurations

No configuration.

History

03 Nov 2025, 19:16

Type	Values Removed	Values Added
References		() https://lists.debian.org/debian-lts-announce/2025/09/msg00004.html -

Information

Published : 2025-08-25 21:15

Updated : 2025-11-03 19:16

NVD link : CVE-2025-57804

Mitre link : CVE-2025-57804

CVE.ORG link : CVE-2025-57804

JSON object : View

Products Affected

No product.

CWE

CWE-93

Improper Neutralization of CRLF Sequences ('CRLF Injection')

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