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CVE-2026-97608

Linux: netfilter: nf_log: unregister loggers before per-net teardown

Linux LinuxOperating systems
Open in ThreatlineRecord JSON
CVSS
7.0High
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.14%Chance of exploitation activity in the next 30 days, higher than 3% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in51417230716b73f6aa1dc402b3a56d3382a694dcAlso 90166834b7dc6131aa42b6b14b8b4ed47be97079, 64803ba0a05791cf9ca874466480e4c4cadaf7ab and 1 moreCVE List
Published25 Sep 2026Updated 19 Oct 2026CVE List

What fixes it

  • 51417230716b73f6aa1dc402b3a56d3382a694dcLinuxCVE List
  • 90166834b7dc6131aa42b6b14b8b4ed47be97079LinuxCVE List
  • 64803ba0a05791cf9ca874466480e4c4cadaf7abLinuxCVE List
  • 2c018cc4842c33f0c732962e2ab58635e8ae5823LinuxCVE List

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

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

netfilter: nf_log: unregister loggers before per-net teardown

nf_log_syslog and nfnetlink_log unregister their per-network namespace operations before unregistering their global logger backends. This leaves a window where a sysctl or netlink writer can rebind the still- registered logger after the per-net pre-exit callback cleared the old selection.

The race looks like this:

CPU 0 CPU 1 ---- ---- unregister_pernet_subsys() nf_log_unset(net, logger) net->nf.nf_loggers[pf] = NULL

lock nf_log_mutex find logger in loggers[][] net->nf.nf_loggers[pf] = logger unlock nf_log_mutex

nf_log_unregister(logger) lock nf_log_mutex loggers[pf][type] = NULL unlock nf_log_mutex synchronize_rcu() module exit returns module core frees backend memory

Later, a sysctl read or packet logging operation can dereference the stale per-net logger pointer.

Fix this by unregistering the global logger backends before tearing down per-net state. Once the global registrations are gone, later writers can no longer rebind the logger. unregister_pernet_subsys() already waits for an RCU grace period after the pre-exit callback clears the per-net selection, while nf_log_unregister() continues to cover readers of the global logger table.

Apply this ordering fix to both nf_log backends that combine per-net teardown with global logger registration.

Text from CVE List

Affected versions 16

  • Linuxaffected: 5b023fc8d8e0997e0b7ea6506d243afd5478c96e before 51417230716b73f6aa1dc402b3a56d3382a694dcCVE List
  • Linuxaffected: 5b023fc8d8e0997e0b7ea6506d243afd5478c96e before b0514ca1ee6f2b708d6c602ea946acdfc6a90e24CVE List
  • Linuxaffected: 5b023fc8d8e0997e0b7ea6506d243afd5478c96e before 90166834b7dc6131aa42b6b14b8b4ed47be97079CVE List
  • Linuxaffected: 5b023fc8d8e0997e0b7ea6506d243afd5478c96e before eaec35fae8f2052c1878a5c7cc7699d8357d79f2CVE List
  • Linuxaffected: 5b023fc8d8e0997e0b7ea6506d243afd5478c96e before 64803ba0a05791cf9ca874466480e4c4cadaf7abCVE List
  • Linuxaffected: 5b023fc8d8e0997e0b7ea6506d243afd5478c96e before dce24f3a146948595bb1b86347f31e20b4975daaCVE List
  • Linuxaffected: 5b023fc8d8e0997e0b7ea6506d243afd5478c96e before 2c018cc4842c33f0c732962e2ab58635e8ae5823CVE List
  • Linuxaffected: 3.10CVE List
  • Linuxunaffected: all versions before 3.10CVE List
  • Linuxunaffected: 5.15.222 through 5.15.*CVE List
  • Linuxunaffected: 6.1.189 through 6.1.*CVE List
  • Linuxunaffected: 6.6.158 through 6.6.*CVE List
  • Linuxunaffected: 6.12.111 through 6.12.*CVE List
  • Linuxunaffected: 6.18.53 through 6.18.*CVE List
  • Linuxunaffected: 7.2.7 through 7.2.*CVE List
  • Linuxunaffected: 7.3CVE List

References 7