What is CVE-2021-39996?

CVE-2021-39996 is a critical-severity vulnerability in Huawei Emui, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2022-01-10.

How severe is CVE-2021-39996?

Critical severity. CVSS v3 base score is 9.8 out of 10.

Buffer overflow in Huawei Emui

CVE-2021-39996

There is a Heap-based buffer overflow vulnerability with the NFC module in smartphones. Successful exploitation of this vulnerability may cause memory overflow.

Vulnerability class: Buffer Overflow

Published 2022-01-10 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.008 (56.3th percentile), scored 2026-09-30.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 56th percentile — 56.3% 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

Huawei Emui — versions 10.0.0, 10.1.0, 10.1.1
Huawei Harmonyos
Huawei Magic Ui — versions 3.0.0, 3.1.0, 3.1.1
Emui;magic Ui;harmonyos — versions EMUI 10.0.0,EMUI 10.1.0,EMUI 10.1.1,EMUI 11.0.0,EMUI 11.0.1, Magic UI 3.0.0,Magic UI 3.1.0,Magic UI 3.1.1,Magic UI 4.0.0, HarmonyOS 2.0

Weakness classification (CWE)

CWE-787 — Out-of-bounds Write

References

device.harmonyos.com/en/docs/security/update/security-bulletins-202112-00000011… (Vendor Advisory)
consumer.huawei.com/en/support/bulletin/2021/12/ (Vendor Advisory)

Frequently asked questions

What is CVE-2021-39996?: CVE-2021-39996 is a critical-severity vulnerability in Huawei Emui, classified under Out-of-bounds Write. CVSS score: 9.8/10. Published 2022-01-10.
How severe is CVE-2021-39996?: Critical severity. CVSS v3 base score is 9.8 out of 10.