The overlayfs implementation in the Linux kernel through 4.5.2 does not properly restrict the mount namespace, which allows local users to gain privileges by mounting an overlayfs filesystem on top of a FUSE filesystem, and then executing a crafted setuid program.
Severity
CVSS 3.1
7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
EPSS
1.1% chance of exploitation in the next 30 days; higher than 66% of CVEs (scores of 2026-10-31)