Puma PROXY Protocol v1 Parser Allows Remote Memory Exhaustion

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-47736
StatePUBLISHED
AssignerGitHub_M
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-07-14 20:17:03 UTC
Updated2026-07-15 18:15:13 UTC
DescriptionPuma 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.

Risk And Classification

Primary CVSS: v3.1 7.5 HIGH from [email protected]

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

EPSS: 0.003500000 probability, percentile 0.272820000 (date 2026-07-19)

Problem Types: CWE-400 | CWE-400 CWE-400: Uncontrolled Resource Consumption

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1CNADECLARED7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Puma Puma affected >= 5.5.0, < 7.2.1 Not specified
CNA Puma Puma affected >= 8.0.0, < 8.0.2 Not specified

References

ReferenceSourceLinkTags
github.com/puma/puma/security/advisories/GHSA-qpgp-93vx-g8v8 [email protected] github.com
github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889f [email protected] github.com
github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58 [email protected] github.com
github.com/puma/puma/releases/tag/v7.2.1 [email protected] github.com
github.com/puma/puma/releases/tag/v8.0.2 [email protected] github.com
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