CVE-2023-0386: Linux Kernel

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

Yes, if you run Linux Kernel. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-06-17, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-07-08; treat that as the outer limit, not the target.
EPSS 7.9%, percentile 95: FIRST’s model estimates a 7.9% chance of exploitation activity in the next 30 days, higher than 95% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
Needs local access needed. Lower urgency for most teams unless an attacker could already run code on the machine.

What it is

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.

CISA’s summary

Linux Kernel contains an improper ownership management vulnerability, 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.

Weakness type: CWE-282.

Product: Linux Kernel · Assigned by: redhat · Published: 2023-03-22

Affected and fixed versions

Vendor	Product	Affected versions (per CVE record)
n/a	Kernel	Linux kernel 6.2-rc6

Severity scores

Scored by	CVSS	Score	Vector
CISA-ADP	3.1	7.8 High	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`

Attack vector: local access needed
Attack complexity: low
Privileges required: low (any account)
User interaction: none
Scope: unchanged

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

CISA KEV: added 2025-06-17; federal due date 2025-07-08. Known ransomware use: Unknown.
CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
CISA SSVC assessment: exploitation active, automatable no, technical impact total.
FIRST EPSS (model of 2026-10-21): 7.88% probability of exploitation activity in the next 30 days; percentile 95.

Timeline

2023-03-22 — CVE record published by redhat
2025-06-17 — Added to CISA’s Known Exploited Vulnerabilities catalog
2025-07-08 — CISA remediation deadline for US federal agencies
2025-10-21 — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Should you act?

What it is

CISA’s summary

Affected and fixed versions

Severity scores

Exploitation and urgency

Timeline

Sources and references

Vendor and project advisories, patches

Vulnerability records

Government

Other references from the CVE record and advisory