What is CVE-2021-3736?

CVE-2021-3736 is a medium-severity vulnerability in Linux Kernel, classified under Information Disclosure. CVSS score: 5.5/10. Published 2022-08-23.

How severe is CVE-2021-3736?

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

Information disclosure in Linux Kernel

CVE-2021-3736

A flaw was found in the Linux kernel. A memory leak problem was found in mbochs_ioctl in samples/vfio-mdev/mbochs.c in Virtual Function I/O (VFIO) Mediated devices. This flaw could allow a local attacker to leak internal kernel information.

Vulnerability class: Information Disclosure

Published 2022-08-23 · 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:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.002 (14.1th percentile), scored 2026-10-01.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 14th percentile — 14.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Linux Kernel
Kernel — versions Fixed in v5.15-rc1

Weakness classification (CWE)

References

bugzilla.redhat.com/show_bug.cgi (Third Party Advisory, Issue Tracking)
access.redhat.com/security/cve/CVE-2021-3736 (Third Party Advisory)
github.com/torvalds/linux/commit/de5494af4815a4c9328536c72741229b7de88e7f (Patch, Third Party Advisory)

Frequently asked questions

What is CVE-2021-3736?: CVE-2021-3736 is a medium-severity vulnerability in Linux Kernel, classified under Information Disclosure. CVSS score: 5.5/10. Published 2022-08-23.
How severe is CVE-2021-3736?: Medium severity. CVSS v3 base score is 5.5 out of 10.