CVE-2026-86547

Exploitation

Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.

SSVC decision

• ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
• AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
• Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.

CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.

EPSS probability

0.18% probability of exploitation activity in the next 30 days.

EPSS percentile

Equal to or higher than the score of 7.5% of scored records. A rank, not a probability.

NVD base score

6.9 (CVSS v4.0), scored by the NVD independently of the CNA.

NVD CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/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 analysis status

Deferred. NVD last modified this record on 2026-09-10.

Red Hat severity

No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

Published

2026-09-09 10:07Z1 MO AGO

Last updated

2026-09-09 12:41Z1 MO AGO

Reserved

2026-09-08

Assigning CNA

VulnCheck

Record state

PUBLISHED

Severity

Medium (CVSS 6.9)

CNA CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Weaknesses

• CWE-476NULL Pointer DereferenceBase

Data version

5.2

Document digest

0a53f12f615e113adf47274ff31d5bd96ad636398bf902c0cb8c41c1fa14fb44

• github.comhttps://github.com/mrubyc/mrubyc/blob/release4.0.0/src/vm.c#L1537technical-description
• github.comhttps://github.com/mrubyc/mrubyc/blob/4261cf5e5ae5579e3110dab98a04b91c7d919429/src/vm.c#L1534technical-description
• www.vulncheck.comVulnCheck Advisory: mrubyc through 4.0.0 NULL Pointer Dereference via OP_ENTERhttps://www.vulncheck.com/advisories/mrubyc-through-4.0.0-null-pointer-dereference-via-op-enterthird-party-advisory