What is CVE-2018-12249?

CVE-2018-12249 is a high-severity vulnerability in Mruby, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2018-06-12.

How severe is CVE-2018-12249?

High severity. CVSS v3 base score is 7.5 out of 10.

Is CVE-2018-12249 known to be exploited?

1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

NULL pointer dereference in Mruby

CVE-2018-12249

An issue was discovered in mruby 1.4.1. There is a NULL pointer dereference in mrb_class_real because "class BasicObject" is not properly supported in class.c.

Published 2018-06-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.021 (81.1th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 81st percentile — 81.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.021 · newest: 0.021 · change: 0.000

Affected products

Mruby — versions 1.4.1
Debian Linux — versions 9.0

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

Public proof-of-concept exploits

nautilus-fuzz/nautilus

References

github.com/mruby/mruby/issues/4037 (Exploit, Third Party Advisory, Issue Tracking)
github.com/mruby/mruby/commit/faa4eaf6803bd11669bc324b4c34e7162286bfa3 (Patch, Third Party Advisory)
lists.debian.org/debian-lts-announce/2022/05/msg00006.html (mailing-list, Mailing List, Third Party Advisory)

Frequently asked questions

What is CVE-2018-12249?: CVE-2018-12249 is a high-severity vulnerability in Mruby, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2018-06-12.
How severe is CVE-2018-12249?: High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2018-12249 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.