What is CVE-2020-36431?

CVE-2020-36431 is a medium-severity vulnerability in Unicorn-Engine Unicorn Engine, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2021-07-20.

How severe is CVE-2020-36431?

Medium severity. CVSS v3 base score is 5.5 out of 10.

Buffer overflow in Unicorn-Engine Unicorn Engine

CVE-2020-36431

Unicorn Engine 1.0.2 has an out-of-bounds write in helper_wfe_arm.

Vulnerability class: Buffer Overflow

Published 2021-07-20 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.003 (17.7th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Unicorn-Engine Unicorn Engine — versions 1.0.2

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

github.com/google/oss-fuzz-vulns/blob/main/vulns/unicorn/OSV-2020-837.yaml (Third Party Advisory)
bugs.chromium.org/p/oss-fuzz/issues/detail (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2020-36431?: CVE-2020-36431 is a medium-severity vulnerability in Unicorn-Engine Unicorn Engine, classified under Out-of-bounds Write. CVSS score: 5.5/10. Published 2021-07-20.
How severe is CVE-2020-36431?: Medium severity. CVSS v3 base score is 5.5 out of 10.