CVE-2026-47737

HIGH

Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections

Title source: cna
STIX 2.1

Description

Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, Puma is vulnerable to source IP spoofing when set_remote_address proxy_protocol: :v1 is enabled and persistent connections are used because Puma incorrectly re-parses PROXY protocol headers after each keep-alive request on the same connection, allowing an attacker to inject a second PROXY header and overwrite REMOTE_ADDR. This issue is fixed in versions 7.2.1 and 8.0.2.

References (7)

Core 7

Scores

CVSS v3 7.5
EPSS 0.0018
EPSS Percentile 7.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-290 CWE-345
Status published
Products (2)
puma/puma >= 5.5.0, < 7.2.1
puma/puma >= 8.0.0, < 8.0.2
Published Jul 14, 2026
Tracked Since Jul 15, 2026