CVE-2026-1979

MEDIUM 5.3

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

CVSS Score

5.3

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-416 CWE-119
Vendor	n/a
Product	mruby
Published	Feb 6, 2026
Last Updated	Feb 23, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C

Attack Vector

Attack Complexity

Privileges Required

User Interaction

Scope

Confidentiality

Integrity

Availability

Affected Versions

n/a / mruby

3.0 3.1 3.2 3.3 3.4.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

vuldb.com: https://vuldb.com/?id.344501 vuldb.com: https://vuldb.com/?ctiid.344501 vuldb.com: https://vuldb.com/?submit.743377 github.com: https://github.com/mruby/mruby/issues/6701 github.com: https://github.com/mruby/mruby/issues/6701#issue-3802609843 github.com: https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415 github.com: https://github.com/mruby/mruby/

Credits

🔍 Oneafter (VulDB User)