What is CVE-2021-39656?

CVE-2021-39656 is a medium-severity vulnerability in Google Android, classified under Use After Free. CVSS score: 6.7/10. Published 2021-12-15.

How severe is CVE-2021-39656?

Medium severity. CVSS v3 base score is 6.7 out of 10.

Use After Free in Google Android

CVE-2021-39656

In __configfs_open_file of file.c, there is a possible use-after-free due to improper locking. This could lead to local escalation of privilege in the kernel with System execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-174049066References: Upstream kernel

Vulnerability class: Use-After-Free

Published 2021-12-15 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.7 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.001 (1.6th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 2nd percentile — 1.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.001 · newest: 0.001 · change: 0.000

Affected products

Google Android
Android — versions Android kernel

Weakness classification (CWE)

References

source.android.com/security/bulletin/pixel/2021-12-01 (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2021-39656?: CVE-2021-39656 is a medium-severity vulnerability in Google Android, classified under Use After Free. CVSS score: 6.7/10. Published 2021-12-15.
How severe is CVE-2021-39656?: Medium severity. CVSS v3 base score is 6.7 out of 10.