CVE-2026-47736
Publication date 14 July 2026
Last updated 16 July 2026
Ubuntu priority
Description
Puma is a Ruby/Rack web server built for parallelism. From 5.5.0 until 7.2.1 and 8.0.2, when PROXY protocol v1 support is enabled, Puma reads incoming bytes into an internal buffer while waiting for CRLF to determine whether a PROXY v1 line is present, allowing an attacker that continuously sends bytes without CRLF to cause unbounded in-process memory growth and additional CPU cost from repeatedly scanning the growing buffer. This issue is fixed in versions 7.2.1 and 8.0.2.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| puma | 26.04 LTS resolute |
Needs evaluation
|
| 24.04 LTS noble |
Needs evaluation
|
|
| 22.04 LTS jammy |
Needs evaluation
|
|
| 20.04 LTS focal |
Needs evaluation
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
7.5 · High
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
References
Other references
- https://www.cve.org/CVERecord?id=CVE-2026-47736
- https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f
- https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58
- https://github.com/puma/puma/releases/tag/v7.2.1
- https://github.com/puma/puma/releases/tag/v8.0.2
- https://github.com/puma/puma/security/advisories/GHSA-qpgp-93vx-g8v8