CVE-2026-86547
mrubyc through 4.0.0 NULL Pointer Dereference via OP_ENTER
- State
- Published
- Severity
- 6.9 Medium
- Published
- Sep 9, 2026
- Updated
- Sep 9, 2026
- Reserved
- Sep 8, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.9 Medium | 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 | VulnCheck |
| 3.1 | 6.2 Medium | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | VulnCheck |
Weaknesses
- CWE-476 NULL Pointer Dereference
Affected Products
| Product | Versions |
|---|---|
mrubycmrubyc |
|
References
- https://github.com/mrubyc/mrubyc/blob/release4.0.0/src/vm.c#L1537technical-description
- https://github.com/mrubyc/mrubyc/blob/4261cf5e5ae5579e3110dab98a04b91c7d919429/src/vm.c#L1534technical-description
- VulnCheck Advisory: mrubyc through 4.0.0 NULL Pointer Dereference via OP_ENTERthird-party-advisory
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