CVE-2023-0386: Linux kernel OverlayFS setuid copy-up privilege escalation

Exploited in the wild High 7.8 EPSS 7.9% Linux kernel

OverlayFS mishandles uid mapping when a capable or setuid file is copied from a nosuid mount into another mount, letting a local user run that file with elevated rights and become root. Fixed upstream in 6.2 (backported to 6.1.9 and 5.15.91); CISA added it to KEV on 17 June 2025.

• CVE-2023-0386CVE identifier
• 7.8CVSS 3.1 base score (high)
• 2025-06-17added to CISA's exploited list (US federal deadline 2025-07-08)
• 7.9%EPSS: chance of exploitation in the next 30 days (higher than 95% of CVEs)
• 2023-03-22published

What do these terms mean? CVE · CVSS score · exploited (KEV) · EPSS · backported fix · all terms

Affected and fixed versions

Affected:

• Linux 5.11 through 5.15.90
• Linux 5.16 through 6.1.8

Fixed in:

• Linux 5.15.91
• Linux 6.1.9
• Linux 6.2

Am I affected?

uname -r
lsmod | grep overlay
sysctl kernel.unprivileged_userns_clone 2>/dev/null; sysctl user.max_user_namespaces

Patch it

Use the commands for your system. Distribution packages often keep an older version number with the fix backported, so compare with the fixed package versions in the table below, not only with the upstream version.

sudo apt update
sudo apt upgrade
sudo reboot

sudo apt update
sudo apt upgrade
sudo reboot

sudo dnf upgrade kernel
sudo reboot

sudo dnf upgrade --refresh kernel

sudo zypper refresh
sudo zypper update kernel-default

sudo dnf upgrade --releasever=latest kernel kernel6.12

sudo pacman -Syu

apk update && apk upgrade linux-lts linux-virt

not Linux

General update steps for every system are on the Linux and Unix & BSD pages; after updating, see which services to restart.

Fix status in Linux distributions

From the Debian security tracker, Ubuntu CVE tracker and Red Hat Security Data API, refreshed every few hours.

If you cannot patch yet

• Red Hat: prevent the overlay module from loading (blacklist it, e.g. echo 'install overlay /bin/false' | sudo tee /etc/modprobe.d/disable-overlay.conf). This breaks Docker/Podman overlay storage.

Sources

• CVE record CVE-2023-0386
• NVD CVE-2023-0386
• CISA KEV entry CVE-2023-0386
• Debian security tracker CVE-2023-0386
• Ubuntu CVE page CVE-2023-0386
• Red Hat CVE page CVE-2023-0386
• Upstream fix commit 4f11ada10d0a
• Debian DSA-5402-1
• https://security.netapp.com/advisory/ntap-20230420-0004/
• https://lists.debian.org/debian-lts-announce/2023/06/msg00008.html
• https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html
• CISA Known Exploited Vulnerabilities catalog

Page generated automatically from official sources on 2026-11-03 18:05 UTC and reviewed by an editor. Always confirm with your vendor's advisory.