What is CVE-2021-4110?

CVE-2021-4110 is a high-severity vulnerability in Mruby, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2021-12-15.

How severe is CVE-2021-4110?

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

NULL pointer dereference in Mruby

CVE-2021-4110

mruby is vulnerable to NULL Pointer Dereference

Published 2021-12-15 · 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: 0.016 (75.3th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 75th percentile — 75.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.016 · newest: 0.016 · change: 0.000

Affected products

Mruby
Mruby Mruby/mruby — versions unspecified

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

huntr.dev/bounties/4ce5dc47-2512-4c87-8609-453adc8cad20 (Exploit, Patch, Third Party Advisory)
github.com/mruby/mruby/commit/f5e10c5a79a17939af763b1dcf5232ce47e24a34 (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-4110?: CVE-2021-4110 is a high-severity vulnerability in Mruby, classified under NULL Pointer Dereference. CVSS score: 7.5/10. Published 2021-12-15.
How severe is CVE-2021-4110?: High severity. CVSS v3 base score is 7.5 out of 10.