What is CVE-2020-36401?

CVE-2020-36401 is a high-severity vulnerability in Linux Kernel, classified under Double Free. CVSS score: 7.8/10. Published 2021-07-01.

How severe is CVE-2020-36401?

High severity. CVSS v3 base score is 7.8 out of 10.

Double Free in Linux Kernel

CVE-2020-36401

mruby 2.1.2 has a double free in mrb_default_allocf (called from mrb_free and obj_free).

Vulnerability class: Double Free

Published 2021-07-01 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.010 (61.1th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 61st percentile — 61.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Linux Kernel
Mruby — versions 2.1.2

Weakness classification (CWE)

CWE-415 — Double Free

References

github.com/mruby/mruby/commit/97319697c8f9f6ff27b32589947e1918e3015503 (Patch, Third Party Advisory)
bugs.chromium.org/p/oss-fuzz/issues/detail (Exploit, Patch, Third Party Advisory, Issue Tracking)
github.com/google/oss-fuzz-vulns/blob/main/vulns/mruby/OSV-2020-744.yaml (Third Party Advisory)

Frequently asked questions

What is CVE-2020-36401?: CVE-2020-36401 is a high-severity vulnerability in Linux Kernel, classified under Double Free. CVSS score: 7.8/10. Published 2021-07-01.
How severe is CVE-2020-36401?: High severity. CVSS v3 base score is 7.8 out of 10.