Vulnerability details

CVE-2026-47737

puma puma

Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections

CVSS 3.1

7.5High

Official 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.

CVSS scores

Score	Version	Source	Vector
7.5High	3.1	CVEProject cvelistV5 (CNA) (GitHub_M)	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N`

Affected products

Vendor	Product	Versions	Source
puma	puma	>= 5.5.0, < 7.2.1	CVEProject cvelistV5 (CNA)
puma	puma	>= 8.0.0, < 8.0.2	CVEProject cvelistV5 (CNA)

References and advisories

https://github.com/puma/puma/security/advisories/GHSA-2vqw-3mp8-cgmx x_refsource_CONFIRM
https://github.com/puma/puma/pull/3944 x_refsource_MISC
https://github.com/puma/puma/pull/3947 x_refsource_MISC
https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f x_refsource_MISC
https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58 x_refsource_MISC
https://github.com/puma/puma/releases/tag/v7.2.1 x_refsource_MISC
https://github.com/puma/puma/releases/tag/v8.0.2 x_refsource_MISC

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Details

Published: 2026-07-14
Last updated: 2026-07-15
State: Published
Assigner (CNA): GitHub_M

Exploit prediction (EPSS)

0.17%

Probability of exploitation in 30 days

7.3%

Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable: Yes
Exploitation: None
Technical impact: Partial

Weaknesses (CWE)

CWE-290
Authentication Bypass by Spoofing
CWE-345
Insufficient Verification of Data Authenticity