CVE-2026-1979CWE-119CWE-416

mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free

Medium · published February 6, 2026

CVSS v4.0
4.8
EPSS
0%
Percentile
7.1
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
4.8 · MEDIUM
Vector
CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
EPSS
0.00179 · 7.1th percentile
Weaknesses
CWE-119 · Improper Restriction of Operations within the Bounds of a Memory Buffer; CWE-416 · Use After Free
Published
2026-02-06T04:32Z
EPSS history
Timeline
  • 06 FEB 04:32Z
    mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free
    cvelistv5