CVE-2025-57804

N/A

Description

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.

CVE Details

CVSS v3.1 ScoreN/A

Published8/25/2025

Last Modified11/3/2025

Sourcenvd

Honeypot Sightings0

Weaknesses (CWE)

CWE-93

References

https://github.com/python-hyper/h2/commit/035e9899f95e3709af098f578bfc3cd302298e3a(security-advisories@github.com)

https://github.com/python-hyper/h2/security/advisories/GHSA-847f-9342-265h(security-advisories@github.com)

https://lists.debian.org/debian-lts-announce/2025/09/msg00004.html(af854a3a-2127-422b-91ae-364da2661108)

IOC Correlations

No correlations recorded

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