Which versions of Mruby are affected by CVE-2026-1979?

Organizations using mruby should be aware of moderate risk from CVE-2026-1979, a buffer overflow vulnerability rated CVSS 5.3. Exploitation could cause memory corruption or application crashes.. A patch is available.

Is there a public PoC exploit available for CVE-2026-1979?

Yes, a public proof-of-concept exploit is available for CVE-2026-1979. Prioritise patching immediately. EPSS: 0.0%.

Mruby CVE-2026-1979

Q: What is the CVSS score of CVE-2026-1979?

CVE-2026-1979 has a CVSS 4.0 base score of 1.9 (Low). CVSS vector: 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 exploitation probability: 0.0%.

LOW

Buffer Overflow (CWE-119)

2026-02-06 cna@vuldb.com

Buffer Overflow Denial Of Service Mruby

1.9

CVSS 4.0 · NVD

Severity by source

NVD PRIMARY

1.9 LOW

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

SUSE

4.3 MEDIUM

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

Primary rating from NVD.

CVSS VectorNVD

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

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Lifecycle Timeline

Severity Changed

Apr 29, 2026 - 01:11 NVD

MEDIUM LOW

CVSS changed

Apr 29, 2026 - 01:11 NVD

5.3 (MEDIUM) 1.9 (LOW)

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Feb 28, 2026 - 00:33 vuln.today

Public exploit code

Patch released

Feb 28, 2026 - 00:33 nvd

Patch available

CVE Published

Feb 06, 2026 - 05:16 nvd

MEDIUM 5.3

DescriptionCVE.org

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.

AnalysisAI

Use-after-free memory corruption in mruby up to version 3.4.0 within the JMPNOT-to-JMPIF optimization logic allows local attackers with user-level privileges to corrupt memory and potentially execute arbitrary code. Public exploit code exists for this vulnerability, and a patch is available. …

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Vulnerability AssessmentAI

Risk Assessment	CVSS 5.3 (MEDIUM). … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario	An attacker could exploit this vulnerability to use after free.
Remediation	A vendor patch is available — apply it immediately. … Detailed patch versions, workarounds, and compensating controls in full report.

Recommended ActionAI

Within 30 days: Identify affected systems running mruby and apply vendor patches as part of regular patch cycle. …

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Vendor StatusVendor

SUSE

Severity: Medium

CVE-2026-1979 vulnerability details – vuln.today

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Mruby CVE-2026-1979

Severity by source

CVSS VectorNVD

Lifecycle Timeline

DescriptionCVE.org

AnalysisAI

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Recommended ActionAI

Vendor StatusVendor

SUSE

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External POC / Exploit Code