CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-47736
High (7.5). EPSS 0.3% chance of exploitation in the next 30 days. Fixed in puma 7.2.1, 8.0.2.
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.
Severity
- EPSS
- 0.3% chance of exploitation in the next 30 days; higher than 28% of CVEs (scores of 2026-10-31)
- CWE
- CWE-400
- Published
- Modified
- Record from
- the NVD, synced
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-qpgp-93vx-g8v8 | RubyGems | puma | >=8.0.0 <8.0.2 | 8.0.2 |
| GHSA-qpgp-93vx-g8v8 | RubyGems | puma | >=5.5.0 <7.2.1 | 7.2.1 |
References
- 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