---
id: CVE-2026-74624
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: nf_conntrack: defer invalid log until after unlock

  TCP and SCTP conntrack paths can emit invalid-packet logs while ct->lock
  is still held.

  When invalid log…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  netfilter: nf_conntrack: defer invalid log until after unlock

  TCP and SCTP conntrack paths can emit invalid-packet logs while ct->lock
  is still held.

  When invalid log…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
published: '2026-08-22'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T13:10:00.187'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-74624'
references:
  - url: 'https://git.kernel.org/stable/c/0424186d570aa4d1ad17f516afb86bd9eaa4f42e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2d19b95c9723001f214f7a47d67b09f46238f200'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/63853eb20bba4e00b7cd0b8cfc19337bbaaf5037'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9480fcf70a5aa9d320088a01c95df0e5e6391f4a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c0224327b7cbed9d3198e8dbec847281053dcd06'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ca97360eba4b3dc67f1804625542f4ccc774242a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00479
epssPercentile: 0.39594
ingestedAt: '2026-10-14T13:30:58.519Z'
---

## Overview

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

netfilter: nf_conntrack: defer invalid log until after unlock

TCP and SCTP conntrack paths can emit invalid-packet logs while ct->lock
is still held.

When invalid logging is routed to nfnetlink_log and conntrack export is
enabled, the log path can re-enter conntrack netlink glue and dump the
same conntrack again. Protocol attribute dumping may take ct->lock, so
logging while holding that lock can deadlock.

Defer the TCP invalid logs by storing only the minimal log context while
ct->lock is held and emitting the log after unlocking. Also make the TCP
timeout-lowering invalid path return whether a log is needed, then emit
that log after unlocking.

Do the same for the SCTP invalid state-transition log that can be reached
while ct->lock is held.

Add a lockdep assertion to nf_ct_l4proto_log_invalid() so future callers
that log invalid conntracks while holding ct->lock are caught outside TCP
and SCTP as well.

## Remediation

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