CVE-2026-1979
mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free
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.
INFO
Published Date :
Feb. 6, 2026, 5:16 a.m.
Last Modified :
Feb. 6, 2026, 5:16 a.m.
Remotely Exploit :
No
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-1979
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 2.0 | MEDIUM | [email protected] | ||||
| CVSS 3.1 | MEDIUM | [email protected] | ||||
| CVSS 4.0 | MEDIUM | [email protected] |
Solution
- Implement the patch e50f15c1c6e131fa7934355eb02b8173b13df415.
- Update mruby to a version containing the fix.
- Monitor for any further security advisories.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-1979.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-1979 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-1979
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-1979 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-1979 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Feb. 06, 2026
Action Type Old Value New Value 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. Added CVSS V4.0 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 Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L Added CVSS V2 (AV:L/AC:L/Au:S/C:P/I:P/A:P) Added CWE CWE-119 Added CWE CWE-416 Added Reference https://github.com/mruby/mruby/ Added Reference https://github.com/mruby/mruby/issues/6701 Added Reference https://github.com/mruby/mruby/issues/6701#issue-3802609843 Added Reference https://github.com/sysfce2/mruby/commit/e50f15c1c6e131fa7934355eb02b8173b13df415 Added Reference https://vuldb.com/?ctiid.344501 Added Reference https://vuldb.com/?id.344501 Added Reference https://vuldb.com/?submit.743377