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CVE-2026-1979

CVE-2026-1979 · mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 4.8 · Medium · EPSS 0.2% · Fix available

Published
Updated

Stack: system

Affected products and versions

  • mruby

    Versions
    • 3.0: Affected
    • 3.1: Affected
    • 3.2: Affected
    • 3.3: Affected
    • 3.4.0: Affected

    No fix published

  • mruby Debian:12

    Versions
    • 3.1.0-3
    • 3.2.0-1
    • 3.2.0-2
    • 3.3.0-1
    • 3.3.0~rc2-1
    • 3.4.0-1
    • 3.4.0-1~exp1
    • 3.4.0-1~exp2
    • 3.4.0-2
    • 3.4.0-3
    • 4.0.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Debian:13

    Versions
    • 3.3.0-1
    • 3.4.0-1
    • 3.4.0-1~exp1
    • 3.4.0-1~exp2
    • 3.4.0-2
    • 3.4.0-3
    • 4.0.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Debian:14

    Versions
    • 3.3.0-1
    • 3.4.0-1
    • 3.4.0-1~exp1
    • 3.4.0-1~exp2
    • 3.4.0-2
    • 3.4.0-3
    Affected ranges
    • ECOSYSTEM: < 4.0.0-1

    Update to 4.0.0-1

  • mruby Ubuntu:16.04:LTS

    Versions
    • 1.1.0+20150817+gita1731254-1
    • 1.1.0+20150906+git1cbbb7e1-1
    • 1.2.0+20160315+git4f20d58a-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Ubuntu:18.04:LTS

    Versions
    • 1.3.0-1
    • 1.3.0+20170925+git38185028-1
    • 1.3.0+20171029+git77edafb0-1
    • 1.4.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Ubuntu:20.04:LTS

    Versions
    • 2.0.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Ubuntu:22.04:LTS

    Versions
    • 2.1.2-3
    • 3.0.0-1
    • 3.0.0-3
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Ubuntu:24.04:LTS

    Versions
    • 3.2.0-1
    • 3.2.0-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Ubuntu:25.10

    Versions
    • 3.3.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Ubuntu:26.10

    Versions
    • 3.4.0-2
    • 3.4.0-3
    • 4.0.0-1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • mruby Ubuntu:26.04:LTS

    Versions
    • 3.3.0-1
    • 3.4.0-2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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