CVE Tools
Sign in

CVE-2026-1979

mruby JMPNOT-to-JMPIF Optimization vm.c mrb_vm_exec use after free

Published: Feb 6, 2026Updated: Apr 29, 2026 Sources: CVE List NVDCWE-119
NVD MITRE
5.3CVSSMEDIUM
EPSS Score
0.2%
Top 95.2%
CISA KEV
Not in KEV
Exploits
1 Known
Remediation
Patch Available

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.

CVSS Vector Breakdown

AV:LAC:LPR:LUI:NS:UC:LI:LA:L
Exploitability
AV:LAttack Vector
Local
AC:LAttack Complexity
Low
PR:LPrivileges Required
Low
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:LConfidentiality
Low
I:LIntegrity
Low
A:LAvailability
Low
Open in CVSS calculator →

Weaknesses

CWE-119CWE-416

Affected Products

mrubyn/a
mrubymruby
LibraryLibrary
OSS Libraries
mrubyoss-projectOSS Libraries

Attack Graph

Products CVE Techniques Tactics

Click technique nodes to view MITRE ATT&CK details. Scroll to zoom, drag to pan.

Exploitability

1 exploit source identified

Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.

View exploit details
Official Patch Available

MITRE ATT&CK

2 techniques
Initial Access
Privilege Escalation
View detailed technique mapping

References

https://vuldb.com/?id.344501
vuldb.com
https://vuldb.com/?ctiid.344501
vuldb.com
https://vuldb.com/?submit.743377
vuldb.com
and 4 more references View all →

Timeline

Published
Feb 6, 2026
Last Updated
Apr 29, 2026

Unlock Complete Vulnerability Intelligence

Get the full picture for CVE-2026-1979 and every CVE in our database. Create a free account — no credit card required.

Create Free Account
Plain-language analysis
Impact assessment and exploitation scenario in plain English
Attack graph visualization
Interactive attack path and kill chain mapping
Exploit details & PoC links
ExploitDB, Metasploit, GitHub PoCs with direct links
Nuclei scanner templates
Ready-to-use vulnerability scanner templates
Full remediation guide
Patch instructions, workarounds, and compliance impact
Interactive AI chat
Ask questions about this vulnerability in natural language
Related vulnerabilities
Semantically similar CVEs and attack patterns
REST API & MCP access
Integrate vulnerability data into your workflows