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HIGH · CVSS 7.8 CISA Known Exploited Vulnerability

CVE-2023-0386

Linux Kernel Improper Ownership Management Vulnerability

Linux Kernel

A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.

CVSS
7.8
HIGH
EPSS
7.9%
30-day exploitation
Ransomware groups
0
recorded exploiting
Published
22 Mar 2023
CWE-282

Exploitation status

CISA Known Exploited Vulnerabilities

Listed by CISA on 17 June 2025. US federal agencies were required to remediate it by 8 July 2025.

EPSS — exploitation probability

FIRST puts the probability of exploitation activity in the next 30 days at 7.9%, which is higher than 94.7% of all scored vulnerabilities. EPSS is a forecast of activity, not a measure of severity, and it is rescored daily.

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Frequently asked questions

Is CVE-2023-0386 being exploited by ransomware groups?

No ransomware group in this database is currently recorded as exploiting CVE-2023-0386.

What does CVE-2023-0386 affect?

CVE-2023-0386 affects Linux Kernel. A flaw was found in the Linux kernel, where unauthorized access to the execution of the setuid file with capabilities was found in the Linux kernel’s OverlayFS subsystem in how a user copies a capable file from a nosuid mount into another mount. This uid mapping bug allows a local user to escalate their privileges on the system.

How severe is CVE-2023-0386?

CVE-2023-0386 is rated HIGH with a CVSS base score of 7.8. EPSS puts the probability of exploitation in the next 30 days at 7.9%, higher than 94.7% of all scored vulnerabilities. It is listed in the CISA Known Exploited Vulnerabilities catalog, with a federal remediation deadline of 8 July 2025.

How should organisations respond to CVE-2023-0386?

Apply the vendor patch for Linux Kernel as the first priority, and treat any internet-facing instance as the most urgent. Because this vulnerability is associated with ransomware activity, also review whether the affected systems were reachable before patching, rather than assuming that patching alone closes the incident.