---
id: CVE-2026-97957
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: hinic: fix mailbox segment buffer overflow

  check_mbox_seq_id_and_seg_len() validates that seq_id does not
  exceed SEQ_ID_MAX_VAL (42) and seg_len does not exceed
  M…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: hinic: fix mailbox segment buffer overflow

  check_mbox_seq_id_and_seg_len() validates that seq_id does not
  exceed SEQ_ID_MAX_VAL (42) and seg_len does not exceed
  M…
severity: high
cvss: 8.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H'
cwe:
  - CWE-787
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= a425b6e1c69ba907b72b737a4d44f8cfbc43ce3c <
    7cc974799fde846eda2d8f00ad4f8e1810eb0499
  - >-
    Linux >= a425b6e1c69ba907b72b737a4d44f8cfbc43ce3c <
    8de1e23bd91fe3a6683e4bc574e2d6bcb0eef920
  - >-
    Linux >= a425b6e1c69ba907b72b737a4d44f8cfbc43ce3c <
    72be1fd5d256dde748c0905c5e1749a119cad5bd
  - >-
    Linux >= a425b6e1c69ba907b72b737a4d44f8cfbc43ce3c <
    c622bbc212207d7c6bbd69dd88f0c3a3f5853d16
  - >-
    Linux >= a425b6e1c69ba907b72b737a4d44f8cfbc43ce3c <
    eca54a092d5f7b497b458ff5a6f66d4f7bfb6674
  - >-
    Linux >= a425b6e1c69ba907b72b737a4d44f8cfbc43ce3c <
    9f6ad383901d0cb1c8ea5f7f3160fabfe1540eb5
  - >-
    Linux >= a425b6e1c69ba907b72b737a4d44f8cfbc43ce3c <
    513f7b16ed0cffae9348151c72bed17c7073096f
  - >-
    Linux >= a425b6e1c69ba907b72b737a4d44f8cfbc43ce3c <
    5d4d985957434867bbe85e4fa5e638f3e48ad522
  - Linux 5.8
published: '2026-09-25'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:18:20.720'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97957'
references:
  - url: 'https://git.kernel.org/stable/c/513f7b16ed0cffae9348151c72bed17c7073096f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5d4d985957434867bbe85e4fa5e638f3e48ad522'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/72be1fd5d256dde748c0905c5e1749a119cad5bd'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7cc974799fde846eda2d8f00ad4f8e1810eb0499'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/8de1e23bd91fe3a6683e4bc574e2d6bcb0eef920'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9f6ad383901d0cb1c8ea5f7f3160fabfe1540eb5'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c622bbc212207d7c6bbd69dd88f0c3a3f5853d16'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/eca54a092d5f7b497b458ff5a6f66d4f7bfb6674'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97957.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-97957'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2541091'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-97957'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97957'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97957.mbox
  - url: 'https://kernelcve.org/list/?q=CVE-2026-97957'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - score-dispute
epss: 0.00143
epssPercentile: 0.03549
scores:
  nvd: 8.8
  vendor: 5.5
  cna: 8.8
ingestedAt: '2026-09-25T11:06:38.876Z'
---

## Overview

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

net: hinic: fix mailbox segment buffer overflow

check_mbox_seq_id_and_seg_len() validates that seq_id does not
exceed SEQ_ID_MAX_VAL (42) and seg_len does not exceed
MBOX_SEG_LEN (48).  However, this allows the last segment
(seq_id=42) to carry a full 48-byte payload, writing to offset
42*48=2016 for 48 bytes (ending at byte 2064).  The receive
buffer is only MBOX_MAX_BUF_SZ (2048) bytes, resulting in a
16-byte heap buffer overflow.

The hinic3 driver already handles this correctly by defining
MBOX_LAST_SEG_MAX_LEN and rejecting the last segment when it
exceeds the remaining buffer space.  Apply the same fix to the
hinic driver.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-21 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97957.json)