---
id: CVE-2023-3812
title: >-
  Kernel: tun: bugs for oversize packet when napi frags enabled in
  tun_napi_alloc_frags
summary: >-
  An out-of-bounds memory access flaw was found in the Linux kernel’s TUN/TAP
  device driver functionality in how a user generates a malicious (too big)
  networking packet when napi frags is enabled. This flaw allows a local user to
  crash or…
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'
cvssSource: cna
cwe:
  - CWE-787
vendor: Red Hat
product: kernel-rt
affected:
  - kernel-rt (all versions)
  - kernel (all versions)
  - kpatch-patch
  - kpatch-patch
  - kernel (all versions)
  - kernel (all versions)
  - kernel-rt (all versions)
  - kernel (all versions)
  - kpatch-patch
  - kernel (all versions)
  - kernel (all versions)
  - kernel-rt (all versions)
  - kernel (all versions)
  - kernel (all versions)
  - kpatch-patch
  - kpatch-patch
  - kernel (all versions)
  - kpatch-patch
  - kernel (all versions)
  - kernel (all versions)
  - kpatch-patch
  - kernel (all versions)
  - kernel (all versions)
  - kernel-rt (all versions)
  - kpatch-patch
  - kernel (all versions)
  - kernel-rt (all versions)
  - kpatch-patch
  - kernel (all versions)
  - kernel
  - kernel
  - kernel-rt
  - kernel-rt (all versions)
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2025-03-05T18:36:18.926997Z'
published: '2023-07-24'
updated: '2026-11-07'
sourceUpdated: '2026-11-07T13:41:44.906Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2023-3812'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2023:6799'
    label: 'RHSA-2023:6799'
  - url: 'https://access.redhat.com/errata/RHSA-2023:6813'
    label: 'RHSA-2023:6813'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7370'
    label: 'RHSA-2023:7370'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7379'
    label: 'RHSA-2023:7379'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7382'
    label: 'RHSA-2023:7382'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7389'
    label: 'RHSA-2023:7389'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7411'
    label: 'RHSA-2023:7411'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7418'
    label: 'RHSA-2023:7418'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7548'
    label: 'RHSA-2023:7548'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7549'
    label: 'RHSA-2023:7549'
  - url: 'https://access.redhat.com/errata/RHSA-2023:7554'
    label: 'RHSA-2023:7554'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0340'
    label: 'RHSA-2024:0340'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0378'
    label: 'RHSA-2024:0378'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0412'
    label: 'RHSA-2024:0412'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0461'
    label: 'RHSA-2024:0461'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0554'
    label: 'RHSA-2024:0554'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0562'
    label: 'RHSA-2024:0562'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0563'
    label: 'RHSA-2024:0563'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0575'
    label: 'RHSA-2024:0575'
  - url: 'https://access.redhat.com/errata/RHSA-2024:0593'
    label: 'RHSA-2024:0593'
  - url: 'https://access.redhat.com/errata/RHSA-2024:1961'
    label: 'RHSA-2024:1961'
  - url: 'https://access.redhat.com/errata/RHSA-2024:2006'
    label: 'RHSA-2024:2006'
  - url: 'https://access.redhat.com/errata/RHSA-2024:2008'
    label: 'RHSA-2024:2008'
  - url: 'https://access.redhat.com/security/cve/CVE-2023-3812'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2224048'
    label: RHBZ#2224048
  - url: >-
      https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=363a5328f4b0
tags:
  - cve.org
epss: 0.00344
epssPercentile: 0.28109
ingestedAt: '2026-11-07T14:18:21.470Z'
---

## Overview

An out-of-bounds memory access flaw was found in the Linux kernel’s TUN/TAP device driver functionality in how a user generates a malicious (too big) networking packet when napi frags is enabled. This flaw allows a local user to crash or potentially escalate their privileges on the system.

## Affected

- `kernel-rt (all versions)`
- `kernel (all versions)`
- `kpatch-patch`
- `kpatch-patch`
- `kernel (all versions)`
- `kernel (all versions)`
- `kernel-rt (all versions)`
- `kernel (all versions)`
- `kpatch-patch`
- `kernel (all versions)`
- `kernel (all versions)`
- `kernel-rt (all versions)`
- `kernel (all versions)`
- `kernel (all versions)`
- `kpatch-patch`
- `kpatch-patch`
- `kernel (all versions)`
- `kpatch-patch`
- `kernel (all versions)`
- `kernel (all versions)`
- `kpatch-patch`
- `kernel (all versions)`
- `kernel (all versions)`
- `kernel-rt (all versions)`
- `kpatch-patch`
- `kernel (all versions)`
- `kernel-rt (all versions)`
- `kpatch-patch`
- `kernel (all versions)`
- `kernel`
- `kernel`
- `kernel-rt`
- `kernel-rt (all versions)`

## Remediation

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

### Workarounds

To mitigate this issue, prevent the tun module from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.