CVE-2011-2686: Ruby-Lang Ruby

Medium severity, CVSS 5.0. EPSS: 2.6% chance of exploitation in the next 30 days.

Ruby before 1.8.7-p352 does not reset the random seed upon forking, which makes it easier for context-dependent attackers to predict the values of random numbers by leveraging knowledge of the number sequence obtained in a different child process, a related issue to CVE-2003-0900. NOTE: this issue exists because of a regression during Ruby 1.8.6 development.

Affected products

• Ruby-Lang Ruby: up to and including 1.8.7-334; version 1.8.7 only; version 1.8.7-160 only; version 1.8.7-173 only; version 1.8.7-248 only; version 1.8.7-249 only; …

Published 2011-08-05. Last modified 2026-06-16.