CVE-2026-86547

mrubyc through 4.0.0 NULL Pointer Dereference via OP_ENTER

Published Sep 9, 2026 CVSS 4.0 · 6.9 Medium EPSS < 1% KEV · Not listed
Description
mrubyc through 4.0.0 contains a null pointer dereference vulnerability in the op_enter() handler in src/vm.c when processing untrusted bytecode. Attackers can craft malicious .mrb bytecode files with OP_ENTER instructions at the top level to crash the embedding application and cause denial of service.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Mruby
Mruby mruby
Vendors & Products Mruby
Mruby mruby
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description mrubyc through 4.0.0 contains a null pointer dereference vulnerability in the op_enter() handler in src/vm.c when processing untrusted bytecode. Attackers can craft malicious .mrb bytecode files with OP_ENTER instructions at the top level to crash the embedding application and cause denial of service.
Title mrubyc through 4.0.0 NULL Pointer Dereference via OP_ENTER
Weaknesses CWE-476
References
Metrics cvssV3_1

{'score': 6.2, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 6.9, '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

Sources

Status
PUBLISHED
Assigner
VulnCheck
Published
Updated
Sep 9, 2026, 12:41 PM
Reserved
Sep 8, 2026, 12:49 AM
Status
Deferred
Published
Sep 9, 2026, 10:22 AM
Modified
Sep 10, 2026, 7:58 PM