CVE-2018-12247: Mruby

High severity, CVSS 7.5. EPSS: 1.5% chance of exploitation in the next 30 days.

An issue was discovered in mruby 1.4.1. There is a NULL pointer dereference in mrb_class, related to certain .clone usage, because mrb_obj_clone in kernel.c copies flags other than the MRB_FLAG_IS_FROZEN flag (e.g., the embedded flag).

Affected products

• Mruby Mruby: version 1.4.1 only

Published 2018-06-12. Last modified 2026-06-17.