PT-2025-34706 · H2+2 · H2+2
CVSS v3.1
9.8
Critical
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Name of the Vulnerable Software and Affected Versions:
h2 versions prior to 4.3.0
Description:
h2 is a pure-Python implementation of a HTTP/2 protocol stack. A request splitting issue 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.
Recommendations:
Update to version 4.3.0 or later.
Exploit
Fix
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Weakness Enumeration
Related Identifiers
Affected Products
Debian
Suse
H2