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TI-2019-12551 Aliases CVE-2019-16770GHSA-7xx3-m584-x994

Potential DOS attack in Puma

Priority LOW 37CWE-770Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 3 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-770.

Summary

In Puma before versions 3.12.2 and 4.3.1, a poorly-behaved client could use keepalive requests to monopolize Puma's reactor and create a denial of service attack. If more keepalive connections to Puma are opened than there are threads available, additional connections will wait permanently if the attacker sends requests frequently enough. This vulnerability is patched in Puma 4.3.1 and 3.12.2.

Why it matters now

EPSS 0.02014 81st percentileScored 2026-11-07
Fix Partial puma (puma): 4.3.1puma (RubyGems): 3.12.2, 4.3.1Red Hat: 3 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
pumapuma< 4.3.1 to before 4.3.14.3.1Patch availableCNA
—puma (RubyGems)before 3.12.23.12.2Patch availableGHSA-7xx3-m584-x994
—puma (RubyGems)4.0.0 to before 4.3.14.3.1Patch availableGHSA-7xx3-m584-x994
  • puma Vendorpuma Affected < 4.3.1 to before 4.3.1 Fixed in 4.3.1 Patch available CNA
  • puma (RubyGems) Vendor— Affected before 3.12.2 Fixed in 3.12.2 Patch available GHSA-7xx3-m584-x994
  • puma (RubyGems) Vendor— Affected 4.0.0 to before 4.3.1 Fixed in 4.3.1 Patch available GHSA-7xx3-m584-x994

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:puma:puma:*:*:*:*:*:ruby:*:*3.0.0 to before 3.12.2; 4.0.0 to before 4.3.1Vulnerablepuma
cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*9.0VulnerableDebian
  • cpe:2.3:a:puma:puma:*:*:*:*:*:ruby:*:* Versions 3.0.0 to before 3.12.2; 4.0.0 to before 4.3.1 Vulnerable ·puma
  • cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Versions 9.0 Vulnerable ·Debian

Remediation

  • Fix · CNA puma (puma) Fixed in 4.3.1
  • Fix · GHSA-7xx3-m584-x994 puma (RubyGems) Fixed in 3.12.2 Advisory →
  • Fix · GHSA-7xx3-m584-x994 puma (RubyGems) Fixed in 4.3.1 Advisory →

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
CloudForms Management Engine 5AffectedNo fix planned: Will not fix
Red Hat Software CollectionsAffectedNo fix planned: Will not fix
Red Hat Storage 3AffectedNo fix planned: Will not fix
Not affected: 1 product
  • Red Hat 3scale API Management Platform 2

Timeline

  1. 2026-10-02 Threatist record created from CVE-2019-16770
  2. 2026-10-03 Alias added: GHSA-7xx3-m584-x994

References

Advisory 4

Other 1

  • TI-2022-08603 HTTP Request Smuggling in puma CVSS 3.1CRITICAL 9.1
  • TI-2023-21048 Inconsistent Interpretation of HTTP Requests in puma CVSS 3.1CRITICAL 9.8
  • TI-2022-07686 Information Exposure when using Puma with Rails CVSS 3.1HIGH 8.0
  • TI-2020-08950 HTTP Smuggling via Transfer-Encoding Header in Puma CVSS 3.1HIGH 7.5
  • TI-2020-08951 HTTP Smuggling via Transfer-Encoding Header in Puma CVSS 3.1HIGH 7.5
  • TI-2020-04303 HTTP Response Splitting in Puma CVSS 3.1HIGH 7.5
See all 11 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences