---
id: CVE-2025-38110
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/mdiobus: Fix potential out-of-bounds clause 45 read/write access

  When using publicly available tools like 'mdio-tools' to read/write data
  from/to network interface…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/mdiobus: Fix potential out-of-bounds clause 45 read/write access

  When using publicly available tools like 'mdio-tools' to read/write data
  from/to network interface…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-125
  - CWE-1284
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 6.3, < 6.6.94'
  - 'linux_kernel >= 6.7, < 6.12.34'
  - 'linux_kernel >= 6.13, < 6.15.3'
  - linux_kernel = 6.16
patched:
  - linux_kernel 6.15.3
published: '2025-07-03'
updated: '2026-10-15'
sourceUpdated: '2026-10-15T22:18:27.633'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-38110'
references:
  - url: 'https://git.kernel.org/stable/c/260388f79e94fb3026c419a208ece8358bb7b555'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/31bf7b2b92563a352788cf9df3698682f659bacc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4ded22f7f3ce9714ed72c3e9c68fea1cb9388ae7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/abb0605ca00979a49572a6516f6db22c3dc57223'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-38110.json
  - url: 'https://access.redhat.com/security/cve/CVE-2025-38110'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2376035'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2025-38110'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2025-38110'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2025070324-CVE-2025-38110-a9c0@gregkh/T
  - url: 'https://access.redhat.com/errata/RHSA-2025:11855'
  - url: 'https://access.redhat.com/errata/RHSA-2025:11245'
  - url: 'https://access.redhat.com/errata/RHSA-2025:11861'
tags:
  - nvd
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00198
epssPercentile: 0.09414
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-15T21:47:30.590466Z'
scores:
  nvd: 7.8
  vendor: 6
  cna: 7.8
ingestedAt: '2026-10-15T22:48:25.493Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

net/mdiobus: Fix potential out-of-bounds clause 45 read/write access

When using publicly available tools like 'mdio-tools' to read/write data
from/to network interface and its PHY via C45 (clause 45) mdiobus,
there is no verification of parameters passed to the ioctl and
it accepts any mdio address.
Currently there is support for 32 addresses in kernel via PHY_MAX_ADDR define,
but it is possible to pass higher value than that via ioctl.
While read/write operation should generally fail in this case,
mdiobus provides stats array, where wrong address may allow out-of-bounds
read/write.

Fix that by adding address verification before C45 read/write operation.
While this excludes this access from any statistics, it improves security of
read/write operation.

## Affected

- `linux_kernel >= 6.3, < 6.6.94`
- `linux_kernel >= 6.7, < 6.12.34`
- `linux_kernel >= 6.13, < 6.15.3`
- `linux_kernel = 6.16`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.15.3`

## Vendor advisories

- **RHSA-2025:11855** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10), Red Hat Enterprise Linux Real Time for NFV (v. 10), Red Hat Enterprise Linux Real Time (v. 10) · released 2025-07-28 · [advisory](https://access.redhat.com/errata/RHSA-2025:11855)
- **RHSA-2025:11245** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream EUS (v.9.4), Red Hat Enterprise Linux BaseOS EUS (v.9.4), Red Hat CodeReady Linux Builder EUS (v.9.4), Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4), Red Hat Enterprise Linux Real Time EUS (v.9.4) · released 2025-07-15 · [advisory](https://access.redhat.com/errata/RHSA-2025:11245)
- **RHSA-2025:11861** · Red Hat · fixed in: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux BaseOS (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9), Red Hat Enterprise Linux Real Time for NFV (v. 9), Red Hat Enterprise Linux Real Time (v. 9) · released 2025-07-28 · [advisory](https://access.redhat.com/errata/RHSA-2025:11861)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 9 · updated 2026-10-16 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2025/cve-2025-38110.json)