---
id: CVE-2026-68338
title: >-
  kernel: net/packet: avoid fanout hook re-registration after unregister
  (CVE-2026-68338)
summary: >-
  A flaw was found in the Linux kernel's `net/packet` subsystem. A race
  condition can occur during the re-registration of a fanout hook after a
  network device has been unregistered. This issue arises when the
  `packet_set_ring()` function att…
severity: high
cvss: 7
cvssVector: 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: vendor
cwe: CWE-367
vendor: Red Hat
product: Red Hat Enterprise Linux 9
affected:
  - enterprise_linux 10
  - enterprise_linux 7
  - enterprise_linux 8
  - enterprise_linux 9
  - enterprise_linux_baseos_v_8
  - enterprise_linux_crb_v_8
patched:
  - enterprise_linux_baseos_v_8
  - enterprise_linux_crb_v_8
published: '2026-08-10'
updated: '2026-10-26'
sourceUpdated: '2026-10-26T09:32:28+00:00'
source: CSAF
sourceUrl: 'https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68338.json'
references:
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68338.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-68338'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2513264'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-68338'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-68338'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2026081036-CVE-2026-68338-8547@gregkh/T
  - url: 'https://access.redhat.com/errata/RHSA-2026:89083'
  - url: 'https://git.kernel.org/stable/c/acb40ebfa5c4d62f84339fcbf713f2a9fd033a71'
  - url: 'https://git.kernel.org/stable/c/c820f4b7f2fa38f8769db0d0cefdd94e2721504d'
  - url: 'https://git.kernel.org/stable/c/4628efbdc7affd094181f5263e65c1062e31f15f'
  - url: 'https://git.kernel.org/stable/c/80ec024d53a05c60ad1d08968dcf745f10c1665c'
  - url: 'https://git.kernel.org/stable/c/0a052e0808e015e68144a9877e6ef42b952c49fa'
  - url: 'https://git.kernel.org/stable/c/1bc55c29cd85818e9052f17deb287d5a11fb817f'
  - url: 'https://git.kernel.org/stable/c/a885387dae7986a55bae5c77a15bdd447f64e9b9'
  - url: 'https://git.kernel.org/stable/c/50aff80475abd3533eef4320477037e6fcc6b56e'
tags:
  - csaf
  - vex
  - red-hat
  - cve.org
epss: 0.00136
epssPercentile: 0.03046
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:47:16.591778Z'
scores:
  vendor: 7
  cna: 7.8
ingestedAt: '2026-10-16T17:24:46.858Z'
---

## Overview

A flaw was found in the Linux kernel's `net/packet` subsystem. A race condition can occur during the re-registration of a fanout hook after a network device has been unregistered. This issue arises when the `packet_set_ring()` function attempts to re-add a fanout hook based on a stale state, potentially leading to an inconsistent system state and a denial of service (DoS).

## Vendor advisories

- **RHSA-2026:89083** · Red Hat · fixed in: Red Hat Enterprise Linux BaseOS (v. 8), Red Hat Enterprise Linux CRB (v. 8) · released 2026-10-24 · [advisory](https://access.redhat.com/errata/RHSA-2026:89083)
- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · updated 2026-10-26 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-68338.json)

**kernel: net/packet: avoid fanout hook re-registration after unregister** — rated Moderate by Red Hat. Released 2026-08-10, updated 2026-10-26.

Affected:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9

Fixed:

- Red Hat Enterprise Linux BaseOS (v. 8)
- Red Hat Enterprise Linux CRB (v. 8)

No fix planned:

- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9

Not affected:

- Red Hat Enterprise Linux 6

## Remediation

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

Red Hat recommends treating all kernel errata as security-relevant. Given the kernel's fundamental role, any bug has a higher chance of impacting system security, even if that impact only becomes clear after a fix is published. Therefore, Red Hat prioritizes delivering fixes that improve our customers' overall security posture.

Because of this proactive approach, a patch may be associa… https://access.redhat.com/errata/RHSA-2026:89083