CVE-2026-47737Puma PROXY Protocol v1 Accepts Repeated Protocol Headers on Persistent Connections
- 7.5HighCVSS base score
- 0.18%Exploitation in 30 daysEPSS · top 93% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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.
Timeline
ID reserved
By GitHub_M
- 56 days later
· 56 days later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| GitHub_MCNA (assigner) | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
| NVDNVD · Deferred | 3.1 | High7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N |
- EPSS (exploitation in 30 days)
- 0.18% · top 93% of all CVEs (13 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: yes · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.5.
Affected products
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemspumaGHSA-2vqw-3mp8-cgmx (opens in a new tab)
References
References7
- https://github.com/puma/puma/security/advisories/GHSA-2vqw-3mp8-cgmx (opens in a new tab)x_refsource_CONFIRM
- https://github.com/puma/puma/pull/3944 (opens in a new tab)x_refsource_MISC
- https://github.com/puma/puma/pull/3947 (opens in a new tab)x_refsource_MISC
- https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f (opens in a new tab)x_refsource_MISC
- https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58 (opens in a new tab)x_refsource_MISC
- https://github.com/puma/puma/releases/tag/v7.2.1 (opens in a new tab)x_refsource_MISC
- https://github.com/puma/puma/releases/tag/v8.0.2 (opens in a new tab)x_refsource_MISC
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-44427 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-2vqw-3mp8-cgmx (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-47737)Record last updated .