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.

Project Subscriptions

Vendors Products
Advisories
Source ID Title
Github GHSA Github GHSA GHSA-2vqw-3mp8-cgmx Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 15 Jul 2026 16:30:00 +0000

Type Values Removed Values Added
First Time appeared Puma
Puma puma
Vendors & Products Puma
Puma puma

Wed, 15 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Wed, 15 Jul 2026 12:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-358
References
Metrics threat_severity

None

threat_severity

Important


Tue, 14 Jul 2026 20:00:00 +0000

Type Values Removed Values Added
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.
Title Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections
Weaknesses CWE-290
CWE-345
References
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2026-07-15T14:10:20.444Z

Reserved: 2026-05-19T22:16:39.503Z

Link: CVE-2026-47737

cve-icon Vulnrichment

Updated: 2026-07-15T14:10:16.549Z

cve-icon NVD

No data.

cve-icon Redhat

Severity : Important

Publid Date: 2026-07-14T19:45:16Z

Links: CVE-2026-47737 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-07-22T09:00:11Z

Weaknesses