CVE-2012-5371: Ruby-Lang Ruby

Medium severity, CVSS 5.0. EPSS: 3.3% chance of exploitation in the next 30 days.

Ruby (aka CRuby) 1.9 before 1.9.3-p327 and 2.0 before r37575 computes hash values without properly restricting the ability to trigger hash collisions predictably, which allows context-dependent attackers to cause a denial of service (CPU consumption) via crafted input to an application that maintains a hash table, as demonstrated by a universal multicollision attack against a variant of the MurmurHash2 algorithm, a different vulnerability than CVE-2011-4815.

Affected products

• Ruby-Lang Ruby: up to and including 1.9.3; version 1.9 only; version 1.9.1 only; version 1.9.2 only; version 1.9.3 only; version 2.0 only

Published 2012-11-28. Last modified 2026-06-16.