CVE-2011-5036: Rack Project Rack

Medium severity, CVSS 5.0. EPSS: 3.9% chance of exploitation in the next 30 days.

Rack before 1.1.3, 1.2.x before 1.2.5, and 1.3.x before 1.3.6 computes hash values for form parameters without restricting the ability to trigger hash collisions predictably, which allows remote attackers to cause a denial of service (CPU consumption) by sending many crafted parameters.

Affected products

• Rack Project Rack: up to and including 1.1.0; version 1.2.0 only; version 1.2.1 only; version 1.2.2 only; version 1.2.3 only; version 1.2.4 only; …

Published 2011-12-30. Last modified 2026-06-16.