CVE-2026-47737

high

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

https://github.com/puma/puma/security/advisories/GHSA-2vqw-3mp8-cgmx

https://github.com/puma/puma/releases/tag/v8.0.2

https://github.com/puma/puma/releases/tag/v7.2.1

https://github.com/puma/puma/pull/3947

https://github.com/puma/puma/pull/3944

https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58

https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f

Details

Source: Mitre, NVD

Published: 2026-07-14

Updated: 2026-07-15

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N

Severity: High

CVSS v3

Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Severity: High

EPSS

EPSS: 0.00015