What is CVE-2021-46023?

CVE-2021-46023 is a high-severity vulnerability in Mruby, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.5/10. Published 2023-02-14.

How severe is CVE-2021-46023?

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

Buffer overflow in Mruby

CVE-2021-46023

An Untrusted Pointer Dereference was discovered in function mrb_vm_exec in mruby before 3.1.0-rc. The vulnerability causes a segmentation fault and application crash.

Vulnerability class: Buffer Overflow

Published 2023-02-14 · 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: 0.008 (54.3th percentile), scored 2026-10-06.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 54th percentile — 54.3% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.008 · newest: 0.008 · change: 0.000

Affected products

Mruby

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

github.com/mruby/mruby/issues/5613 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2021-46023?: CVE-2021-46023 is a high-severity vulnerability in Mruby, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 7.5/10. Published 2023-02-14.
How severe is CVE-2021-46023?: High severity. CVSS v3 base score is 7.5 out of 10.