{"id":"CVE-2026-86547","summary":"mrubyc through 4.0.0 NULL Pointer Dereference via OP_ENTER","details":"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.","modified":"2026-09-12T03:30:52.341775368Z","published":"2026-09-09T10:07:25.743Z","database_specific":{"cna_assigner":"VulnCheck","cwe_ids":["CWE-476"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86547.json"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86547.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-86547"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/mrubyc-through-4.0.0-null-pointer-dereference-via-op-enter"},{"type":"PACKAGE","url":"https://github.com/mrubyc/mrubyc"},{"type":"ARTICLE","url":"https://github.com/mrubyc/mrubyc/blob/4261cf5e5ae5579e3110dab98a04b91c7d919429/src/vm.c#L1534"},{"type":"ARTICLE","url":"https://github.com/mrubyc/mrubyc/blob/release4.0.0/src/vm.c#L1537"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mrubyc/mrubyc","events":[{"introduced":"4f904e0dea407e3cc47c29cb4bf717eecb2921c1"},{"fixed":"434bccd609f2a3e90d6bb95c458621898bc6a508"}],"database_specific":{"source":["AFFECTED_FIELD","DESCRIPTION"],"extracted_events":[{"introduced":"2.0"},{"last_affected":"4.0.0"},{"introduced":"0"},{"fixed":"4.0.0"}]}}],"versions":["release3.4.1","release3.4","release3.3.1","release3.3","release3.2","release3.2-rc1","release3.2-beta1","release3.1","release2.1","release2.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-86547.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}