CVE-2026-1979

Name: CVE-2026-1979
Creator: NVD / NIST
Published: 2026-02-06T05:16:12.667+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

LOWCVSS 1.9/10EPSS 0.15%

Last modified Jun 17, 2026

CVE-2026-1979 is a low-severity vulnerability rated 1.9/10 on the CVSS scale. 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. EPSS estimates a 0.15% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS 4.0

1.9/10

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

EPSS Probability

0.15%

4.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Mruby	Mruby	<= 3.4.0

References

https://github.com/mruby/mruby/Product
https://github.com/mruby/mruby/issues/6701Exploit, Issue Tracking
https://github.com/mruby/mruby/issues/6701#issue-3802609843Exploit, Issue Tracking
https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415Patch
https://vuldb.com/?ctiid.344501Permissions Required, VDB Entry
https://vuldb.com/?id.344501Third Party Advisory, VDB Entry
https://vuldb.com/?submit.743377Third Party Advisory, VDB Entry

Timeline

Published: Feb 6, 2026
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2026-1979?

How severe is CVE-2026-1979?

CVE-2026-1979 has a CVSS score of 1.9/10 (LOW severity). The EPSS model estimates a 0.15% probability of exploitation in the next 30 days.

How do I fix CVE-2026-1979?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-1979?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST