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.
CVE-2026-47736
HIGHPre-NVD 7.57.5—
EchelonGraph scoreMEDIUM confidence
This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.4%, top 73% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: epss, secondary
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
- High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.5(medium)
- EG Risk
- —
- EPSS
- 27.5%
- KEV
- Not listed
Published
June 8, 2026
Last Modified
July 15, 2026
Advisory Details (5)
Auto-updated Jul 15, 2026Patch available. Sources: github_commit, github_release, github.
github Patch Available
Puma PROXY Protocol v1 Parser Allows Remote Memory Exhaustion · Advisory · puma/puma · GitHub
https://github.com/puma/puma/security/advisories/GHSA-qpgp-93vx-g8v8github_release Patch Available
v8.0.2
Patch available: puma/puma v8.0.2
https://github.com/puma/puma/releases/tag/v8.0.2github_release Patch Available
v7.2.1
Patch available: puma/puma v7.2.1
https://github.com/puma/puma/releases/tag/v7.2.1github_commit Patch Available
commit ebe9db3929ab (puma/puma)
Patch available: puma/puma v7.2.1 (contains commit ebe9db3929ab)
https://github.com/puma/puma/commit/ebe9db3929ab8299d19c8f5b41e8ef4f4b22fa58github_commit Patch Available
commit 439c6136d9c2 (puma/puma)
Patch available: puma/puma v8.0.2 (contains commit 439c6136d9c2)
https://github.com/puma/puma/commit/439c6136d9c2275721b7864db3ee78af7c80889fVendor Advisories for CVE-2026-47736(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Affected Packages
(1 across 1 ecosystem)
RubyGems(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| puma | 5.5.0 ... 7.2.0 (37 versions) | 7.2.1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 7× in last 7d / 8× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-22 14:08 UTCEPSS rescore
- 2026-07-21 15:24 UTCEPSS rescore
- 2026-07-20 17:08 UTCEPSS rescore
- 2026-07-19 14:31 UTCEPSS rescore
- 2026-07-19 02:29 UTCEPSS rescore
- 2026-07-18 10:04 UTCEPSS rescore
- 2026-07-16 17:03 UTCEPSS rescore
- 2026-07-15 16:57 UTCEPSS rescore
- 2026-06-14 23:18 UTCEPSS rescore
- 2026-06-13 23:00 UTCEPSS rescore
- 2026-06-12 23:12 UTCEPSS rescore
- 2026-06-09 00:00 UTCEG score recompute
Related CVEs(same CWE)
Same CWE
10 shownCWE-400
- CVE-2013-20004EG 9.8CRITICAL
- CVE-2011-3192NVD 0.0EG 9.0EPSS 100%NONE
- CVE-2004-1464NVD 5.9EG 9.0 KEVEPSS 92%MEDIUM
- CVE-2006-1364NVD 7.5EG 8.2EPSS 99%HIGH
- CVE-2007-20001EG 7.5HIGH
- CVE-2002-20001EG 7.5EPSS 98%HIGH
- CVE-2012-0785EG 7.5HIGH
- CVE-2012-5366EG 7.5HIGH
- CVE-2012-5365EG 7.5HIGH
- CVE-2012-5364EG 7.5EPSS 96%HIGH
Frequently asked(5)
What is CVE-2026-47736?
CVE-2026-47736 is a high vulnerability published on June 8, 2026. 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…
When was CVE-2026-47736 disclosed?
CVE-2026-47736 was first published in the National Vulnerability Database on June 8, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-47736 actively exploited?
CVE-2026-47736 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 27.5% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-47736?
CVE-2026-47736 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-47736?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-47736, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2026-47736
Is Your Infrastructure Affected by CVE-2026-47736?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.