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

Configurations

No configuration.

History

26 Aug 2025, 13:41

Type	Values Removed	Values Added
Summary		(es) h2 es una implementación puramente en Python de una pila de protocolos HTTP/2. Antes de la versión 4.3.0, una vulnerabilidad de división de solicitudes HTTP/2 permitía a los atacantes realizar ataques de contrabando de solicitudes mediante la inyección de caracteres CRLF en los encabezados. Esto ocurre cuando los servidores degradan las solicitudes HTTP/2 a HTTP/1.1 sin validar correctamente los nombres/valores de los encabezados, lo que permite a los atacantes manipular los límites de las solicitudes y eludir los controles de seguridad. Este problema se ha corregido en la versión 4.3.0.

25 Aug 2025, 21:15

Type	Values Removed	Values Added
New CVE

Information

Published : 2025-08-25 21:15

Updated : 2025-08-26 13:41

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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