CVE-2023-0386Known exploitationPublic exploit

Local privilege escalation via invalid UID mapping

Published Mar 22, 2023 · Updated Oct 21, 2025

Improper ownership management in Linux kernel OverlayFS before 6.2-rc6 allows local users to gain root privileges through copy-up. The OverlayFS copy-up path fails to reject an inode whose UID or GID lacks a mapping in the current user namespace, preserving privileged file attributes in the upper layer. Exploitation requires low-privileged local access, user and mount namespaces, FUSE, OverlayFS, and a writable upper filesystem that permits setuid execution; success yields root execution.

CVSS severity7.8
High
EPSS probability7.88%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper ownership management in Linux kernel OverlayFS before 6.2-rc6 allows local users to gain root privileges through copy-up. The OverlayFS copy-up path fails to reject an inode whose UID or GID lacks a mapping in the current user namespace, preserving privileged file attributes in the upper layer. Exploitation requires low-privileged local access, user and mount namespaces, FUSE, OverlayFS, and a writable upper filesystem that permits setuid execution; success yields root execution.

The record

CVE
CVE-2023-0386
Published
Mar 22, 2023
Updated
Oct 21, 2025
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-282, T1068
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 22, 2023CVE publishedPublication date reported by the CVE source.
  2. Jun 17, 2025Exploitation reportedCISA Known Exploited Vulnerabilities listing
  3. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Linux kernel 6.2-rc6

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=Linux kernel 6.2-rc6

Published CVSS scores

7.8UbuntuCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-282Improper Ownership Management
T1068Exploitation for Privilege Escalation

Public exploit references

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Reported exploitation

Technologies

Your stack

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Your stack

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