CVE-2013-0263: Rack Project Rack

Medium severity, CVSS 5.1. EPSS: 5.4% chance of exploitation in the next 30 days.

Rack::Session::Cookie in Rack 1.5.x before 1.5.2, 1.4.x before 1.4.5, 1.3.x before 1.3.10, 1.2.x before 1.2.8, and 1.1.x before 1.1.6 allows remote attackers to guess the session cookie, gain privileges, and execute arbitrary code via a timing attack involving an HMAC comparison function that does not run in constant time.

Affected products

• Rack Project Rack: version 1.5.0 only; version 1.5.1 only; version 1.4.0 only; version 1.4.1 only; version 1.4.2 only; version 1.4.3 only; …

Published 2013-02-08. Last modified 2026-06-16.