Description
Puma is a web server for Ruby/Rack applications built for parallelism. Prior to version 6.4.2, puma exhibited incorrect behavior when parsing chunked transfer encoding bodies in a way that allowed HTTP request smuggling. Fixed versions limits the size of chunk extensions. Without this limit, an attacker could cause unbounded resource (CPU, network bandwidth) consumption. This vulnerability has been fixed in versions 6.4.2 and 5.6.8.
Scores
CVSS v3
5.9
EPSS
0.0246
EPSS Percentile
85.3%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-444
Status
published
Products (2)
puma/puma
< 5.6.8
rubygems/puma
6.0.0 - 6.4.2RubyGems
Published
Jan 08, 2024
Tracked Since
Feb 18, 2026