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.

Metrics

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact Low

Vulnerable System Integrity Impact Low

Vulnerable System Availability Impact Low

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact Low

Integrity Impact Low

Availability Impact Low

User Interaction None

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact Low

Integrity Impact Low

Availability Impact Low

User Interaction None

Access Vector Local

Access Complexity Low

Authentication Single

Confidentiality Impact Partial

Integrity Impact Partial

Availability Impact Partial

This CVE is not in the KEV list.

Exploitation poc

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Mruby
  • Mruby

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References
Link Providers
https://github.com/mruby/mruby/ cve-icon cve-icon
https://github.com/mruby/mruby/issues/6701 cve-icon cve-icon
https://github.com/mruby/mruby/issues/6701#issue-3802609843 cve-icon cve-icon
https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415 cve-icon cve-icon
https://vuldb.com/?ctiid.344501 cve-icon cve-icon
https://vuldb.com/?id.344501 cve-icon cve-icon
https://vuldb.com/?submit.743377 cve-icon cve-icon
History

Fri, 06 Feb 2026 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Fri, 06 Feb 2026 12:15:00 +0000

Type Values Removed Values Added
First Time appeared Mruby
Mruby mruby
Vendors & Products Mruby
Mruby mruby

Fri, 06 Feb 2026 04:45:00 +0000

Type Values Removed Values Added
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.
Title mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free
Weaknesses CWE-119
CWE-416
References
Metrics cvssV2_0

{'score': 4.3, 'vector': 'AV:L/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:OF/RC:C'}

cvssV3_0

{'score': 5.3, 'vector': 'CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C'}

cvssV3_1

{'score': 5.3, 'vector': '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'}

cvssV4_0

{'score': 4.8, '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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: VulDB

Published: 2026-02-06T04:32:09.200Z

Updated: 2026-02-06T20:26:21.865Z

Reserved: 2026-02-05T13:44:19.662Z

Link: CVE-2026-1979

cve-icon Vulnrichment

Updated: 2026-02-06T20:26:18.193Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-02-06T05:16:12.667

Modified: 2026-02-06T15:14:47.703

Link: CVE-2026-1979

cve-icon Redhat

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