CVE-2021-3732
kernel: overlayfs: Mounting overlayfs inside an unprivileged user namespace can reveal files
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · August 12, 2021
Updated · June 28, 2026
Description
A flaw was found in the Linux kernel’s OverlayFS subsystem in the way the user mounts the TmpFS filesystem with OverlayFS. This flaw allows a local user to gain access to hidden files that should not be accessible.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 3.3CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor