CVE-2026-1979: mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free
A flaw has been found in mruby up to 3.4.0. This affects the function mrbvmexec 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.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-1979?
CVE-2026-1979 is a critical vulnerability due to a use after free issue that can allow for manipulation and potential exploitation.
How do I fix CVE-2026-1979?
To fix CVE-2026-1979, upgrade to mruby version 3.4.1 or later, as this version addresses the vulnerability.
Which versions of mruby are affected by CVE-2026-1979?
CVE-2026-1979 affects all mruby versions up to and including 3.4.0.
What type of vulnerability is CVE-2026-1979?
CVE-2026-1979 is classified as a use after free vulnerability in the JMPNOT-to-JMPIF Optimization functionality.
Can CVE-2026-1979 lead to remote code execution?
Yes, CVE-2026-1979 can potentially allow attackers to execute arbitrary code if exploited successfully.