CVE-2026-1979
mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free
MEDIUM 4.8
At a glance
- Source
- NVD
- EPSS
- EPSS 0.18 % · percentile 7 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- VulDB
- NVD status
- Analyzed
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.
Weaknesses (CWE)
- CWE-416 — Use After Free
- CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer
References
- https://vuldb.com/?id.344501
- https://vuldb.com/?ctiid.344501
- https://vuldb.com/?submit.743377
- https://github.com/mruby/mruby/issues/6701
- https://github.com/mruby/mruby/issues/6701#issue-3802609843
- https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415
- https://github.com/mruby/mruby/
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 4.0 | MEDIUM 4.8 | 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 | VulDB |
| CVSS 3.1 | MEDIUM 5.3 | 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 | VulDB |
| CVSS 3.0 | MEDIUM 5.3 | 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 | VulDB |
| CVSS 2.0 | MEDIUM 4.3 | AV:L/AC:L/Au:S/C:P/I:P/A:P/E:POC/RL:OF/RC:C | VulDB |
| CVSS 4.0 | LOW 1.9 | 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/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X | NVD · cna@vuldb.com (Secondary) |
| CVSS 3.1 | MEDIUM 5.3 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L | NVD · cna@vuldb.com (Secondary) |
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
| CVSS 2.0 | MEDIUM 4.3 | AV:L/AC:L/Au:S/C:P/I:P/A:P | NVD · cna@vuldb.com (Secondary) |
European references
- ENISA EUVD · EUVD-2026-5583
- GCVE · GCVE-0-2026-1979
Affected configurations (NVD CPE)
cpe:2.3:a:mruby:mruby:*:*:*:*:*:ruby:*:*≤ 3.4.0
Affected products
| Product | Versions |
|---|---|
| mruby | affected 3.0 ; affected 3.1 ; affected 3.2 ; affected 3.3 ; affected 3.4.0 |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |