Vulnerability in Puma
CVE-2026-47737
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 incorr…
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.
Affected products
- Puma — versions >= 5.5.0, < 7.2.1, >= 8.0.0, < 8.0.2
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC)
Frequently asked questions
- What is CVE-2026-47737?
- CVE-2026-47737 is a high-severity vulnerability in Puma, classified under Authentication Bypass by Spoofing. CVSS score: 7.5/10. Published 2026-07-14.
- How severe is CVE-2026-47737?
- High severity. CVSS v3 base score is 7.5 out of 10.