CVE-2026-1979

Medium

Description

A flaw has been found in mruby up to 3.4.0. This affects the function mrb_vm_exec of the file src/vm.c of the component JMPNOT-to-JMPIF Optimization. Executing a manipulation can lead to use after free. The attack needs to be launched locally. The exploit has been published and may be used. This patch is called e50f15c1c6e131fa7934355eb02b8173b13df415. It is advisable to implement a patch to correct this issue.

SeverityMedium

CVSS5.3

Exploit probability—

ProductMruby

PublishedFeb 6, 2026

First seenFeb 6, 2026

Weakness typeCWE-416Use after free CWE-119Memory buffer bounds error

How to fix

Patches

github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415

Affected products

Product	Affected versions	Fixed in
mruby mruby	v ≤ 3.4.0	—

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.