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.

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact None

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
puma puma affected
Version Status Constraints
>= 5.5.0, < 7.2.1 affected —
>= 8.0.0, < 8.0.2 affected —

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Project Subscriptions

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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.

References
Link Providers
https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f cve-icon
https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58 cve-icon
https://github.com/puma/puma/pull/3944 cve-icon
https://github.com/puma/puma/pull/3947 cve-icon
https://github.com/puma/puma/releases/tag/v7.2.1 cve-icon
https://github.com/puma/puma/releases/tag/v8.0.2 cve-icon
https://github.com/puma/puma/security/advisories/GHSA-2vqw-3mp8-cgmx cve-icon
History

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: 2026-07-14T19:45:16.648Z

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

Link: CVE-2026-47737

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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Weaknesses