{"cve":"CVE-2026-86547","nvd":{"published":"2026-09-09T10:22:33.803","modified":"2026-09-10T19:58:20.507","status":"Deferred","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.","cvss_v4":{"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","score":6.9},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":6.2},"cwes":["CWE-476"],"references":["https://github.com/mrubyc/mrubyc/blob/4261cf5e5ae5579e3110dab98a04b91c7d919429/src/vm.c#L1534","https://github.com/mrubyc/mrubyc/blob/release4.0.0/src/vm.c#L1537","https://www.vulncheck.com/advisories/mrubyc-through-4.0.0-null-pointer-dereference-via-op-enter"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:52:53.108888569+00:00"},"epss":{"cve":"CVE-2026-86547","score":0.00184,"percentile":0.07964,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}