CVE-2018-12248: 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 heap-based buffer over-read associated with OP_ENTER because mrbgems/mruby-fiber/src/fiber.c does not extend the stack in cases of many arguments to fiber.

Affected products

• Mruby Mruby: version 1.4.1 only

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